[2019] TASSC 26

Torts - Negligence - Procedure and evidence - Evidence - Proof of causation generally - Circumstantial evidence - Damage caused by high voltage electricity entering low voltage system - Three possible routes - Multiple asserted breaches of duties of care - Whether plaintiff required to establish a particular breach of duty was causative.

Civil Liability Act 2002 (Tas), ss 13(1)(a), 13(2), 14.

Re Belhaven and Stenton Peerage (1875) 1 App Cas 278; Langmaid v Dobsons Vegetable Machinery Pty Ltd [2014] TASFC 6, 24 Tas R 18; Attorney-General's Reference (No 4 of 1980) [1981] 1 WLR 705, referred to.

Judgment Number: [2020] TASFC 4

BROCKLANDS PTY LTD v TASMANIAN NETWORKS PTY LTD

2 Judgment for respondent and ancillary orders as to costs set aside.

1. Judgment to be entered for the appellant against the respondent for damages to be assessed by a judicial officer other than the learned trial judge.

BROCKLANDS PTY LTD v TASMANIAN NETWORKS PTY LTD

1. The appellant company, Brocklands Pty Ltd, conducts a nursery business at Winkleigh in the north of Tasmania. On 10 December 2010 there was an interruption to the electricity supply at its nursery. At that time Aurora Energy Pty Ltd ("Aurora") was responsible for providing electricity to the property. The relevant liabilities of that company and its predecessor the Hydro-Electric Commission ("the HEC"), were transferred to the respondent, Tasmanian Networks Pty Ltd, in 2014 pursuant to s 19 of the Electricity Reform Act 2012. In 2015 the appellant brought an action for damages against the respondent, contending that it suffered harm as a result of the interruption to the electricity supply and breaches of duty on the part of Aurora and/or the HEC. It claimed more than $2.5 million by way of damages in respect of the alleged breaches of duty. The action was tried by Geason J over 14 days in the autumn and winter of 2018. The action failed. His Honour gave judgment for the respondent: Brocklands Pty Ltd v Tasmanian Networks Pty Ltd [2019] TASSC 26. This is an appeal from that judgment.
2. The principal findings made by the learned trial judge were as follows:
   • At [60], that the appellant's claim was not a claim for pure economic loss.
   • At [77], that a common law claim for damages for negligence had not been pleaded by the appellant.
   • At [101], that none of various breaches of statutory duty pleaded by the appellant conferred any private right of action. (That finding is not challenged by the appellant.)
   • At [156]-[262], that the appellant had failed to establish causation - that is, that it had failed to establish that the damage that it suffered was caused in any of the ways alleged by it.
3. The appellant's principal contentions in the appeal are to the following effect:
   • That, contrary to the conclusion of the learned trial judge, a common law claim for damages for negligence was sufficiently pleaded in its amended statement of claim. (Ground 1.)
   • That in evaluating the appellant's case, which was based on circumstantial evidence, his Honour erred by considering parts of the evidence in isolation from one another, rather than making an assessment of the combined strength of all the pieces of circumstantial evidence. (Ground 2.)
   • That the circumstantial evidence, properly assessed, compels a conclusion that the respondent is liable to it for damages for negligence. (Grounds 3-16 assert specific errors in relation to the assessment of the circumstantial evidence.)
4. The electricity for the appellant's nursery is generated in Trevallyn. High voltage electricity (22,000 volts) travels about 14 kilometres along high voltage ("HV") lines until it reaches a pole on the appellant's property, identified as pole 343836 ("the pole"). The pole has a transformer on it. Low voltage ("LV") electricity (230-240 volts) then travels from the pole to the nursery. The appellant is the only recipient of electricity from that pole.
5. On the night of 10 December 2010, a branch from a tree fell across an HV power line several kilometres away from the nursery. As a result, a circuit breaker called a recloser, located at Glengarry, cut off the power and then switched it back on again very quickly. It did that four times and then locked out. The appellant's case at trial was that the operation of the recloser caused a power surge; that that resulted in HV electricity entering the LV system on the appellant's property; that that happened because hardware on and below the pole was not configured or installed correctly; and that the HV electricity caused damage to a "program logic controller" ("the PLC") inside the appellant's potting machine. Its claim for damages was based on the damage said to have been caused in that way, including alleged consequential losses.
6. The respondent contended that the HEC and Aurora did not owe the appellant a common law duty of care. The learned trial judge did not address that issue because he concluded that no claim in negligence had been pleaded. The respondent further contended that there had been no breach of any asserted duty of care, and that the evidence fell short of proving that the appellant's damage had been caused by the incorrect configuration or installation of any of the hardware on or below the pole.
7. At trial, the appellant identified three ways by which it contended that HV electricity was likely to have entered the LV system:
   • By flashing over from a transformer component referred to as the HV right hand bushing to a cable known as an LV conductor.
   • By flashing over from a transformer component called a spark gap rod to an LV conductor.
   • By passing through the ground from an HV earthing conductor to an LV earthing conductor.
8. The appellant accepts that, in relation to each of these three hypotheses considered alone, the evidence fell short of establishing on the balance of probabilities that the HV electricity travelled as suggested. However the appellant contends that the evidence establishes the following on the balance of probabilities:
   • That it is possible that HV electricity entered the LV system in each of the three suggested ways.
   • That but for negligence on the part of the HEC and Aurora, it would not have been possible for HV electricity to enter the LV system in any of those ways.
   • That HV electricity must have entered the LV system in one or more of those ways.
9. On that basis, the appellant contends that it should be found as a fact, established on the balance of probabilities, that the damage to the PLC and all consequential damage resulted from negligence on the part of the HEC and Aurora.

1. The appellant amended its statement of claim on a number of occasions while the action was pending. The final version was an amended statement of claim dated 23 March 2018. That was the pleading in which, according to the learned trial judge, no cause of action in negligence was pleaded. The amended statement of claim began with appropriate assertions as to the appellant, its nursery business, Aurora and its responsibility for the electricity distribution network within Tasmania, the respondent, and the transfer to it of the liabilities of Aurora. Thereafter, the amended statement of claim included the following:

"6 At all times from the date of the installation of the pole until the present the Hydro Electric Commission of Tasmania or its successor in title, Aurora Energy Pty Ltd was responsible for the installation and maintenance of the distribution network through which electricity was supplied to the property for use by the Plaintiff in conducting its business.

1. Electricity was supplied to the property from power pole 343836, which includes, amongst other things, a transformer ('the pole').
2. By reason of the Industry Act it was the duty of Aurora Energy Pty Ltd to supply electricity in accordance with the Tasmanian Electricity Code.

1. To provide electricity at a voltage within the range provided for in paragraph 8.6.4 'Voltage' of the Tasmanian Electricity Code.
2. To provide electricity in accordance with paragraph 8.7(a) 'Safety and Other Manuals' of the Tasmanian Electricity Code.

1. On 10 December 2010 good electricity industry practice, as defined in the Tasmanian Electricity Code, for the supply of electricity in Australia complies with:-

1. AS 2067:2008 being the applicable Australian Standard for the design and erection of electrical power installations. 2. AS 7000:2010 being the applicable Australian Standard for the determination of separation between different power circuits on the same support (attached crossing).

1. The Energy Networks Association Code ENA 007:2006 Section 5.10.4 specifying 280 mm clearance lines to earth for a 24 kV highest system voltage.

1. AS 2067:1984 being the applicable Australian Standard for earth matting. 2. Any relevant engineering drawing(s) prepared by the Defendant or its predecessors in title including HEC Drawings B12335 and B14731. 3. Inspection of overhead lines for component defects pursuant to Aurora Procedure 'Identification and Management of Overhead Line Defects' NP RAM03
2. Accordingly, the scope of the Hydro Electric Commission and Aurora Energy Pty Ltd's duty to the Plaintiff in the supply and distribution of electricity to the property required it to:-

1. Install an earthing system at the pole in accordance with AS2067:2008 and Drawing BI4731 with sufficient separation of HV and LV earth systems such that danger to persons or equipment could not occur in the low voltage installation as a result of an HV fault or surge and described in Drawing BI4731 at 2m. 2. Install an earthing system at the pole in accordance with AS2067:2008 with an earth resistance value such that the rise of voltage of the earthing system is less than 2000V above true earth potential.

1. Install the pole with a clearance distance between the transformer HV bushing and the LV conductor of not less than 280 mm, and to fail to ensure from November 1989 that there was a minimum 310mm clearance between the HV and LV conductors.

1. Maintain a minimum separation on the pole between phase and earth of 220 mm for a BIL of 125 kV and 280 mm for a BIL of 145 kV. 2. Supply and install bare and unpainted arc gap rods on the pole. 3. Install arc gap rods on the pole with the correct separation as provided in Drawing Bl2335 of 50mm in series. 4. Ensure that the pole complied with the accepted industry practice and Drawing B14731 that the resistance of the HV and LV earthing systems not exceed 30 ohms. 5. Provide, in accordance with AS 2067:1984, an earthing system on the pole for both HV and LV of sufficiently low resistance. 6. Provide earthing systems on the pole for both HV and LV either: 1. in accordance with AS 2067:1984; or, 2. in accordance with AS 2067:2008. 7. Inspect overhead lines for component defects every three (3) years.
2. At diverse times during fault or surge events between approximately 1988 and 2012, but more particularly on 10 December 2010, the voltage to the property exceeded the range permitted by the Tasmanian Electricity Code.
3. On 10 December 2010 the pole did not comply with paragraph 8.7(a) of the Tasmanian Electricity Code.
4. On 10 December 2010 the clearance between the transformer HV bushing and the LV conductor on the pole was approximately 110 mm.
5. On 10 December 2010 the arc gap rods on the pole were covered in paint.
6. On 10 December 2010 the left hand side bushing on the pole had a misaligned arc gap rod thereby creating an incorrect separation of 15mm in series and the right hand side arc gap rod had an incorrect separation of 10mm in series
7. On 10 December 2010 the resistance of the HV earthing system fitted to the pole was approximately 97 ohms.
8. On 10 December 2010 the earthing system for the pole was not in accordance with:
   1. AS 2067:1984; or,
   2. AS 2067:2008.
9. Each of the matters pleaded in paragraphs 11 to 17 inclusive constituted a negligent breach of duty by the Defendant.

1. The high voltage entered the low voltage system at or around the pole.
2. On 10 December 2010 the method by which high voltage electricity entered the low voltage system was by one or both of the following mechanisms:-
   • Transfer of high voltage electricity within the transformer attached to the pole ('the transformer') from the HV transformer bushing to the LV active 'a' conductor; and/or,
   • Transfer of high voltage electricity from the HV earthing system to the LV earthing system by way of induced voltage during a fault or surge event.

The mechanisms referred to above were caused by one or more of the following negligent acts or omissions of the Defendant:

• The pole was poorly designed and installed by the Defendant (formerly the HEC) and not in accordance with the required standards causing the HV transformer bushing to be within 220mm (presuming BIL of 125kV) of the LV active 'a' conductor; namely 110mm. This incorrect proximity increases the likelihood of high voltage electricity entering the low voltage system of the Plaintiffs premises causing damage.
• The spark gaps of the transformer right hand side HV bushing were misaligned. The spark gaps were approximately 60 mm in series when Hydro Electric Commission ('HEC') diagram B12335 required a separation of 25mm for each spark gap. This incorrect separation reduced the effectiveness of the transformer HV earthing system and increases the likelihood that electricity, following the path of least resistance, would enter the LV system in order to find a less resistive earth.
• The arc gap rods on the transformer right hand HV bushing were painted. Drawing B12335 does not prescribe painted rods. Further, it is not good electricity industry practice for arc gap rods to be painted because even a thin layer of paint has the effect of reducing the effectiveness of the rods when operation is required in a fault or surge event leading high voltage electricity to find less resistive paths to earth than otherwise designed.
• The HV and LV earthing system electrodes were placed approximately 300mm apart. By placing earth electrodes closer than is permitted in AS 2067:1984 or AS2067:2008 or Drawing B14731 it was possible for high voltage during a fault or surge event to become induced into the LV earthing electrode at a sufficient voltage as to cause damage to the Plaintiffs plant and equipment.
• The earthing system of the pole was not sufficient to yield a resistance value of less than 30 ohms as required by relevant standards and HEC drawing B14731. The resistance of the HV earthing system for the transformer was approximately 97 ohms as measured by the Defendant. The high resistance of the HV earthing system increased the likelihood that electricity, following the path of least resistance, would enter either the LV earthing system by way of induction or cause an 'arc!' or 'flash' from the transformer right hand HV bushing to the LV active 'a' conductor allowing dangerously high voltage during a fault or surge event to travel from the pole to the Plaintiffs premises causing damage to plant and equipment.
• Failure to identify and/or report and/or prioritise and/or attend to the defects referred to in paragraph 18(i) of this Statement of Claim.

1. By reason of one or more of the matters pleaded in paragraph 11 to 17 inclusive, high voltage entered the low voltage system supplying the property and caused harm.

The harm was caused on or about 10 December 2010 by voltage exceeding the maximum permitted by the Tasmanian Electricity Code for a 240V installation entering the 240V circuits of the Plaintiffs premises by reason of one or more of the mechanisms and factors particularised above.

The harm was the destruction of a Mitsubishi FX2N Programmable Logic Controller ('PLC') that was used to operate a Demtec Potting Machine and Potting Robot.

The PLC sustained catastrophic damage to internal components due to a power surge which caused the PLC (and thus the Demtec equipment) to fail to operate.

1. In the event it is found that none of the alleged breaches were a necessary element of the occurrence of the harm, this is an exceptional case within the meaning of Section 13(2) of the Civil Liability Act 2002.

1. The only causative factors relate to breach of duty.
2. All the breaches of duty were imposed on the Defendant and no other party.

1. As a matter of common sense one or more of the Defendant's breaches caused the damage.

1. For the purposes of deciding the scope of liability (pursuant to Section 13(4) of the Civil Liability Act 2002) the responsibility for the harm suffered by the Plaintiff should be imposed on the Defendant for the following reasons:-

1. The Defendant had a statutory responsibility to supply electricity. 2. The supply of electricity is essential.

1. The negligent supply of electricity can cause injury, death and/or damage to property. 2. The Plaintiff relies on the Defendant to design, install and maintain infrastructure and to supply electricity in a safe manner. 3. The Defendant has significant experience in the operation of an electricity distribution network. 4. The Defendant has significant resources at its disposal to ensure compliance with its statutory and common law duties."
2. It can be seen that in the amended statement of claim, the appellant pleaded details of the relationship between it and the respondent, the statutory transfer of the liabilities of the HEC and Aurora to the respondent, the facts relied upon as the basis of its contentions as to how HV electricity entered the LV system, its suffering of harm, and the causation of that harm. However the amended statement of claim did not contain an express assertion that the HEC and Aurora owed the appellant common law duties requiring them to take reasonable care to prevent HV electricity from entering the LV system or any similar duties.
3. The learned trial judge concluded that, because of that omission, no cause of action in negligence had been pleaded. The respondent contends that he was correct. The appellant contends that he was incorrect, and that the express pleading of such duties was unnecessary. It contends that it was sufficient for it to plead only the facts giving rise to common law duties of care, as distinct from the existence of the duties. It contends that its reliance on the tort of negligence as a basis for its claim for damages was made clear in par 18 of the pleading which read, "Each of the matters pleaded in paragraphs 11 to 17 inclusive constituted a negligent breach of duty by the Defendant", and then set out detailed "particulars of negligence".
4. Counsel for the respondent submitted from the beginning of the trial that negligence had not been pleaded. The reasoning of the learned trial judge that led to him upholding that submission can be summarised as follows:
   • At [72] he said, "The pleadings omit a statement, expressly pleaded or by reference to some other aspect of the pleadings, of the legal relationship relied upon for the purposes of establishing a duty of care in common law."
   • At [73] he observed, "The existence of a statutory duty can never be a sufficient basis on its own for the creation of a common law duty of care. There will always be some other element, such as obligations flowing from a relationship between the parties ...".
   • At [71] and [74], he treated par 18 as pleading only breaches of statutory duties. At [74] he said, "... merely adding the label 'negligent' does not elevate a reference to them to the pleading of an action in negligence".
   • At [75], he accepted a submission made by counsel for the respondent to the effect that the pleading did not make clear whether an established duty or a novel one was being asserted.
   • At [66], he expressed the view that the Civil Liability Act 2002 requires a pleading to address "the duty, and the scope of the duty". He distinguished my decision in Jones v Clyde Welshpool Pty Ltd [2000] TASSC 130, 9 Tas R 391. I held in that case, at [9], that "a statement of claim is quite capable of disclosing a cause of action in negligence if only the facts alleged to give rise to a duty are pleaded, and no assertion is made as to the existence of any duty". His Honour distinguished that case on the basis that it predated the Civil Liability Act.
5. There is nothing in the Supreme Court Civil Procedure Act 1932, the Supreme Court Rules 2000 or the Civil Liability Act that expressly requires a plaintiff to plead anything as to the existence or scope of an asserted duty of care. Rule 227(1)(b) of the Supreme Court Rules requires a pleading to "contain only a statement of all the material facts in summary form on which the party relies but not the evidence by which those facts are to be proved". Rule 227(3) says that "Every pleading is to be expressed so as to give reasonably explicit notice to any other party of all grounds of action ... on which the party pleading intends to rely at the trial."
6. As a general rule, because a plaintiff is required only to plead facts that show an entitlement to relief, there is no need to plead conclusions of law. That has been the situation ever since the adoption of the Judicature Act system of pleading. Thus, in Konskier v B Goodman Limited [1928] l KB 421, Scrutton LJ, with whom Sargent and Greer LJJ agreed, said, at, 427:

"But a plaintiff is not now bound to state the legal effect of the facts on which he relies; he is only bound to state the facts themselves ...".

I followed that case in Jones v Clyde Welshpool Pty Ltd (above).

1. Statements of claim often contain paragraphs in which asserted duties of care are pleaded and carefully defined. The inclusion of such a paragraph is often a good idea. Sometimes it is essential in order to give the defendant "reasonably explicit notice" of the basis of the plaintiff's claim, as required by r 227(3).
2. The only relevant provisions in the Civil Liability Act concerning a duty to take reasonable care are ss 11 and 12. Those sections read as follows;

"11(1) A person does not breach a duty to take reasonable care unless -

(a) there was a foreseeable risk of harm (that is, a risk of harm of which the person knew or ought reasonably to have known); and

(c) in the circumstances, a reasonable person in the position of the person would have taken precautions to avoid the risk.

(2) In deciding whether a reasonable person would have taken precautions against a risk of harm, the court is to consider the following (among other relevant things):

(a) the probability that the harm would occur if care were not taken;

(c) the burden of taking precautions to avoid the risk of harm;

(d) the potential net benefit of the activity that exposes others to the risk of harm.

(3) For the purpose of subsection (2)(c), the court is to consider the burden of taking precautions to avoid similar risks of harm for which the person may be responsible.

12 In a proceeding relating to liability for breach of duty -

(a) the fact that a risk of harm could have been avoided by doing something in a different way does not of itself give rise to or affect liability for the way in which the thing was done; and

(b) the subsequent taking of action that (had the action been taken earlier) would have avoided a risk of harm does not of itself give rise to or affect liability in relation to the risk and does not of itself constitute evidence of liability in connection with the risk."

1. In my view the enactment of those sections has not made it necessary for plaintiffs always to plead matters relating to each paragraph of s 11. That is because the Civil Liability Act did not change the ingredients of a cause of action for negligence. The facts relied upon by the appellant in this case were what it had to plead, and the relevant sections made no difference as to what facts were material. It will often be sufficient for a plaintiff to plead that the defendant was negligent, and to provide particulars of negligence listing the acts and omissions that are said to have constituted negligence, or breaches by the defendant of a duty of care. That is what the appellant did in this case. Its assertion in par 18 of the pleading that each of several pleaded matters "constitute a negligent breach of duty" and its provision of particulars of negligence were sufficient, in the words of r 227(3), to give the respondent "reasonably explicit notice ... of all grounds of action" on which it intended to rely at the trial.
2. Ground 1 must succeed. It is as plain as day that a cause of action in negligence was sufficiently pleaded.

1. At the trial, the following matters, amongst others, were agreed between the parties:
   • The HEC generated, transmitted and distributed electricity in Tasmania until 1 July 1998 when, pursuant to a notice under the Electricity Companies Act 1997, all assets, rights and liabilities in respect of the distribution business of the HEC were transferred to Aurora.
   • On 1 July 2014, pursuant to a notice under the Electricity Reform Act, all assets, rights and liabilities in respect of Aurora's distribution business passed to the respondent.
   • In each notice, "distribution business" referred to the "poles and wires" transferring HV and LV electricity from sub-stations to residential homes and small businesses.
   • The HEC "dressed and installed" the pole in or around 1987.
   • The transformer on the pole was installed as part of the original installation and had not been replaced.
   • In 1998 the appellant leased the property at Winkleigh.
   • In May 2002 it purchased the property.
2. It was common ground that the respondent did not assume responsibility for any of the liabilities relating to the generation of electricity, as distinct from its distribution, by the HEC or Aurora.
3. The dangers relating to electricity have been well known for many years. They were perhaps less well known in 1850 when, according to some sources, William Gladstone, then the Chancellor of the Exchequer, asked Michael Faraday what practical value electricity had, and was told, "Why, sir, there is every probability that you will soon be able to tax it." Judicial notice can now be taken of the fact that electrocution can cause death or serious injury, and of the fact that electrical equipment can be damaged or destroyed by the transmission of electricity at too high a voltage.
4. There is no shortage of cases in which entities responsible for the transmission or distribution of electricity have been held to have owed duties of care to persons who might suffer harm as a result of electrocution or damage to electrical equipment.
5. Thompson v Bankstown Corporation [1953] HCA 5; (1953) 87 CLR 619 concerned a boy who climbed an electricity pole to try to reach a bird's nest and received an electric shock from an earth-wire. The Bankstown Corporation conducted an electricity undertaking, distributing electricity throughout its municipality. The High Court held that it owed the boy a duty of care because its exercise of statutory powers involved something dangerous. Submissions that the case should be decided on the basis that the boy was a trespasser upon the corporation's structure were rejected. Dixon CJ and Williams J said, at 629:

"But it appears to us to be an artificial and unreal view of the situation in the present case to treat it as depending on the extent of the defendant's duty arising from the possession of the pole.

The generation, or receipt, and transmission of electrical energy of a lethal voltage imposed the duty upon the defendant. By statute, as we assume, the defendant was authorized to bring it upon the highway. But a duty of care rested upon the defendant of a high degree; a duty of care measured by a high standard both because of the lethal nature of the agency and because of the almost infinite variety of mischance by which attempts to insulate it and prevent its escape may be defeated. Obvious as it may be, it is necessary to remember that the elevation of the high tension transmission wires upon poles is the first step in discharging that duty. That is the purpose and function of the pole upon which the vertical wire remained that brought disaster to the plaintiff."

"The defendant's liability ... arises because it was under a duty to take reasonable care while maintaining upon a public road poles and wires for the transmission of electricity of a very dangerous voltage."

"Now the appellant, as a member of the public using a road along which the respondent was engaged in transmitting its electric power, was one to whom injury might reasonably be foreseen as a likely consequence of any omission on the part of the respondent to take reasonable care in the management of its electricity; and, that being so, there clearly was a relation between the parties by reason of which it was the respondent's duty to take reasonable care to safeguard the appellant against the consequences of any such omission."

1. That case was followed in Munnings v Hydro-Electric Commission [1971] HCA 27; (1971) 125 CLR 1. That case also concerned a boy who climbed an electricity pole and was accidentally electrocuted. At 11, Barwick CJ held that Thompson was "an authority for the proposition that a person bringing such a substance as electricity into proximity of the public owes a duty to take care by the adoption of reasonable steps or methods that it does not harm those whom it ought to foresee might otherwise come into contact with it". Menzies and Windeyer JJ also took that view.
2. Counsel for the respondent argued that the appellant's claim did not fall within any accepted category of duty, and that it was therefore necessary to undertake an analysis of the "salient features" of the relationship between the parties in order to determine whether there was a duty of care. It is certainly correct that such an analysis is necessary when the circumstances of a case fall outside any accepted category of duty: Perre v Apand Pty Ltd [1999] HCA 37, 198 CLR 180 at [198]; Graham Barclay Oysters Pty Ltd v Ryan [2002] HCA 54, 211 CLR 540 at [149], [243]. In the light of the High Court's decisions in Thompson and Munnings it is clear that the duty of an entity that transmits electricity to persons who might foreseeably suffer harm as a result of the transmission of electricity in an unintended way is an accepted category of duty.
3. Of course this case concerns damage to property, whereas Thompson and Munnings both concerned personal injuries. A cause of action in respect of property damage is not the same cause of action as one relating to personal injury caused by the same negligence: Brunsden v Humphrey [1884] UKLawRpKQB 158; (1884) 14 QBD 141. However there is no reason to distinguish Thompson and Munnings on that basis. The precautions that an electricity distributor needs to take in order to discharge its duty to take reasonable care to prevent the electrocution of individuals are the same precautions that need to be taken to prevent damage to electrical equipment. If HV electricity enters an LV system, there is not just a risk that electrical equipment will be damaged, but also a risk that anyone using or touching electrical equipment will be electrocuted. It follows that the duty of an entity that transmits electricity that is owed to persons who might foreseeably suffer harm as a result of the transmission of electricity in an unintended way is an accepted category of duty that relates not just to personal injury, but also to property damage.
4. If I am wrong about that, I think that an analysis of the salient features of the relationship between the parties compels a conclusion that the HEC and Aurora owed the appellant a duty to take reasonable care to prevent property damage resulting from the transmission of electricity at an unintended voltage.
5. I say that because of the following facts and circumstances:
   • The HEC and Aurora were responsible at all material times for the distribution of electricity to the consumers of electricity throughout Tasmania.
   • The consumers of electricity from their network included the proprietors of many small businesses in which electrically powered machinery was used.
   • The appellant is and was the proprietor of a small business using electrically powered machinery.
   • It is generally known that electrically powered machinery is invariably designed to operate at a particular voltage or range of voltages.
   • The appellant's claim relates to damage to its electrically operated machinery caused by the transmission of electricity at too high a voltage for certain of its machinery to withstand, and for consequential losses.
   • The HEC and Aurora installed, maintained and controlled the infrastructure through which electricity was transmitted to the appellant's property, including the pole, the transformer and equipment on it, the cables bringing HV electricity to it, and earthing cables connected to it.
   • The appellant relied on Aurora to supply electricity at such a voltage that its machinery would work and not be damaged or destroyed.
   • The appellant was vulnerable to harm to its machinery. As the proprietor of a nursery business it had little or no capacity to protect its equipment from power surges. It was not reasonable in the circumstances to expect it to take steps to protect itself against power surges.
   • If a surge of HV electricity entered the appellant's LV system, there was not just a risk that the appellant's electrical equipment would be damaged, but also a risk that anyone using or touching that equipment might be electrocuted.
   • The evidence at the trial established that the HEC and Aurora routinely took steps to obviate the risk of power surges in the design and installation of transformers. In particular, they routinely installed and designed transformers maintaining safe distances between bushings and consumers' LV conductors, by ensuring that the gaps between spark gap rods were small enough to eliminate the risk of flashovers to consumers' LV conductors, and by maintaining safe distances between the uninsulated sections of HV and LV earthing conductors.
   • The cost of taking steps to obviate the risk of the appellant's machinery being damaged by a power surge was modest.
   • The harm that a power surge could potentially cause to the appellant was substantial, particularly because of the risk of an interruption to its business causing substantial financial loss.
   • There was no potential indeterminacy of liability since the duty asserted was a duty to a single electricity consumer who was the sole consumer of electricity from a single pole.
   • The imposition of the asserted duty would not interfere with the right or ability of the respondent to discharge its duties under the relevant legislation.
6. For these reasons it is very clear that the HEC and Aurora owed the appellant duties to take reasonable steps to protect the appellant's machinery from damage from power surges.

1. Counsel for the respondent submitted that the appellant's claim should be characterised as a claim for pure economic loss, not as a claim in respect of property damage and consequential losses. I disagree.
2. Damages for pure economic loss are not recoverable if all that is shown is that the defendant's negligence was a cause of the loss and the loss was reasonably foreseeable: Woolcock Street Investments Pty Ltd v CDG Pty Ltd [2004] HCA 16, 216 CLR 515 per Gleeson CJ, Gummow, Hayne and Heydon JJ at [21]. It was held in Caltex Oil (Australia) Pty Ltd v The Dredge "Willemstad" [1976] HCA 65; (1976) 136 CLR 529 that, as a general rule, damages are not recoverable for economic loss which is not consequential upon injury to person or property, even if the loss is foreseeable. However, as Gibbs J said in that case at 544, "... it is clearly settled that where personal injury or physical damage to property has been caused by a negligent act, the damages which may be recovered include compensation for all pecuniary loss suffered as a result of the injury or damage."
3. The appellant's case was that the negligence of the HEC and Aurora resulted in a power surge which damaged its PLC, causing an interruption to its production and substantial economic loss. Its claim included components for a loss of profits, borrowing costs, a liability to refund money to an insurer, and interest.
4. Its claim as pleaded did not include a component in respect of damage to the PLC. That does not affect the way in which its claim should be categorised. It is a claim for pecuniary loss suffered as a result of physical damage to property. This is not a case in which a claim is defeated by the common law rule as to pure economic loss.

1. In his reasons at [110]-[260] the learned trial judge undertook an analysis of the appellant's case as to causation. He considered various aspects of the evidence in isolation from one another, and made a series of findings that were favourable to the respondent, as follows:
   • His Honour considered the evidence of numerous incidents from 2003 until 2011 when there were interruptions to the appellant's power supply associated with electrical appliances failing or being damaged. At [153] he concluded that he was not able to draw any inference from those episodes.
   • At [155] his Honour said that he afforded no weight to the evidence about those interruptions to the power supply and the damage sustained by electrical appliances.
   • As to the hypothesis that HV electricity could have passed through the ground from an HV earthing conductor to an LV earthing conductor, his Honour said at [173] that that issue required the Court to be satisfied that the appellant had proved on the balance of probabilities that the earthing system resistance was greater than 30 ohms on 10 December 2010, and that uninsulated earth wires were located less than two metres apart. At [178], his Honour concluded that he was not satisfied on the balance of probabilities that on that date the earthing system resistance was greater than 30 ohms, and continued, "It follows that the Court is not satisfied that the harm could have been caused by a mechanism which relies upon this fact."
   • At [191] his Honour concluded that he was not satisfied that the location of the earth wires, as alleged, was established. He made a finding to the effect that the passing of electricity from the HV earth wire to the LV earth wire as hypothesised was possible, but that the evidence established only that it was possible. He continued, "As such the existence of that fact does not go beyond conjecture, and is not sufficient to establish the matters on the balance of probabilities."
   • At [192], he said, "It follows that the causation mechanism based upon the earths is not established; it is not open to the Court to find that the location of the earth wires could have caused the harm."
   • At [201], his Honour made a finding that it was possible that HV electricity had entered the LV system as the result of a flashover event, but he went on to conclude that the appellant had not proved that that had occurred. He said, "The evidence led by the plaintiff goes no further than to establish that it is possible. The court finds that the existence of these facts is not proved; it is mere conjecture. It is not sufficient to establish the matters relied upon, on the balance of probabilities."
   • At [202], his Honour noted that the parties had agreed that the right hand spark gap was 60 mm in series, and accepted that the left hand spark gap was 65 mm in series. At [203], his Honour said he was satisfied that, with that configuration, there was a mechanism through which an HV surge could find its way to the LV pathway. However he held that he was not satisfied that the appellant had proved that there was such an event.
   • At [204], his Honour considered the state of the evidence as to the painting of an arc gap rod. He concluded that he could not be satisfied that, by reason of the painting of the arc gap rod, there was a mechanism through which causation might be established.
   • At [211], his Honour said that he was satisfied, on the basis of the respondent's expert evidence, supported by the modelling evidence from one of its expert witnesses, Dr Muthumuni, that the appellant had not established a surge event of the magnitude alleged, nor that the respondent's acts or omissions were a necessary element of the harm to the PLC. He went on to set out his reasons for that conclusion at [212]-[258], referring in detail to the evidence of the parties' expert witnesses. At [259] he repeated his conclusion that the appellant had "not established on the balance of probabilities that there was a high voltage surge event in December 2010 which damaged the PLC".
2. The proper approach to a case based on circumstantial evidence is as stated by Lord Cairns in Re Belhaven and Stenton Peerage (1875) 1 App Cas 278 at 279:

"... in dealing with circumstantial evidence, we have to consider the weight which is to be given to the united force of all the circumstances put together. You may have a ray of light so feeble that by itself it will do little to elucidate a dark corner. But on the other hand, you may have a number of rays, each of them insufficient, but all converging and brought to bear upon the same point, and, when united, producing a body of illumination which will clear away the darkness which you are endeavouring to dispel."

1. The case law as to wholly circumstantial civil cases was usefully summarised by Porter J in Langmaid v Dobsons Vegetable Machinery Pty Ltd [2014] TASFC 6, 24 Tas R 18 at [119]- [126]. The following propositions were made clear by his Honour's analysis:
   • "Where circumstantial evidence is relied upon, it is not in general necessary that all reasonable hypotheses consistent with the non-existence of a fact, or inconsistent with its existence, be excluded before the fact can be found". "A rational choice between competing hypotheses, informed by a sense of actual persuasion in favour of the choice made, will support a finding, on the balance of probabilities, as to the existence of the fact in issue." Nguyen v Cosmopolitan Homes (NSW) Pty Ltd [2008] NSWCA 246 per McDougall J (with whom McColl and Bell JJA agreed) at [55].
   • "All that is necessary is that according to the course of common experience the more probable inference from the circumstances ... should be that the injury arose from the defendant's negligence. By more probable is meant no more than upon a balance of probabilities such an inference might reasonably be considered to have some greater degree of likelihood." Bradshaw v McEwans Pty Ltd (1951) 217 ALR 1 at 6.
   • "Evidence of possibility is capable of supporting a probative inference, and expert evidence of possibility may, as circumstantial evidence, alone or in combination with other evidence, establish causation": Langmaid, per Porter J at [124], citing Seltsam Pty Ltd v McGuiness [2000] NSWCA 29, 49 NSWLR 262 per Spigelman CJ at [89]; McDonald v Girkaid Pty Ltd [2004] NSWCA 297, Aust Torts Reports 81-768, per McColl JA (with whom Beazley JA and Young CJ in Eq agreed) at [104].
2. In Langmaid, the appellant's case was that "hot work" undertaken by the respondent had caused a fire. There were two other possibilities that had to be considered, namely a possibility that the fire was not caused by hot work at all, and a possibility that it was caused by hot work undertaken by an employee of one of the appellants. At [126], Porter J indicated that it was necessary to acknowledge "the combined strength of the possibilities that the fire was not caused by hot work at all, and that it was caused by the hot work of the first appellant's employee". Similarly, in this case, it is necessary to evaluate the "combined strength" of the possibilities asserted by the appellant.
3. That is not what the learned trial judge did. At the beginning of the passage in his reasons relating to causation, he said, at [157], "Each of the factual matters upon which the plaintiff relies to prove causation must be proved by it on the balance of probabilities". His Honour seems to have regarded it as axiomatic that proof of causation in this case required the identification of at least breach of duty that was established on the balance of probabilities to have caused or materially contributed to the appellant's damage. Similarly, counsel for the respondent, in their submissions to this Court, appear to have regarded that as axiomatic. The respondent's submissions as to causation appear to assume that a claim for damages for negligence cannot succeed without the claimant establishing on the balance of probabilities that there has been both a breach of a duty of care and a suffering of harm resulting from that particular breach. However the appellant's contentions are based on the premise that, where there are pieces of circumstantial evidence akin to strands in a cable, it is sufficient to establish on the balance of probabilities that there were breaches of duty, that harm was suffered, and that the harm must have resulted from one or more breaches of duty, even if no individual breach of duty can be identified as causative.
4. This is no ordinary case. I have been unable to find any civil case in which findings have been made as to multiple breaches of duty, damage resulting from one or more of those breaches of duty, and insufficient evidence for the causative breaches to be established. There are certainly cases that stand for the proposition that a plaintiff does not need to establish precisely how an injury was suffered: Hamilton v Nuroof (WA) Pty Ltd [1956] HCA 42; (1956) 96 CLR 18 at 23-24; Kuhl v Zurich Financial Services Australia Ltd [2011] HCA 11, 243 CLR 361 at [53]- [54]; Duma v Mader International Pty Ltd [2013] VSCA 23, 42 VR 351 at [3]; Langmaid v Dobsons Vegetable Machinery Pty Ltd (above) at [141]. However those cases did not involve distinct breaches of duty, competing possible causes of harm, and a shortage of evidence pointing to one or more particular causes.
5. A criminal case involving multiple possible causes of harm has been considered by the English Court of Appeal: Attorney-General's Reference (No 4 of 1980) [1981] 1 WLR 705. That reference related to the trial of a man who was acquitted on a charge of manslaughter. The Crown alleged that he had killed a woman, but the woman's body was never found. On the evidence there were three possible causes of death. She might have died as a result of the accused pushing her and causing her to fall and hit her head, or as a result of the accused strangling her with a rope, or as a result of him cutting her throat. The trial judge held that the Crown bore the burden of proving beyond reasonable doubt which act caused the woman's death, and that the evidence was insufficient for the jury to be satisfied beyond reasonable doubt that any particular act was the cause of death. He therefore directed an acquittal. Ackner LJ, reading the opinion of the Court of Appeal, said, at 710:

"... this reference raises a single and simple question, viz: if an accused kills another by one or other of two or more different acts each of which, if it caused the death, is a sufficient act to establish manslaughter, is it necessary in order to found a conviction to prove which act caused the death? The answer to that question is 'No, it is not necessary to found a conviction to prove which act caused the death'. No authority is required to justify this answer, which is clear beyond argument ...".

1. For a jury to convict on circumstantial evidence alone in a criminal case "the circumstances must exclude any reasonable hypothesis consistent with innocence": Chamberlain v The Queen (No 2) [1984] HCA 7; (1984) 153 CLR 521 per Gibbs CJ and Mason J at 536. There is nothing in that principle that requires a jury to conclude that an accused person committed the crime charged in a particular manner when the evidence leaves open the possibility that the accused committed the crime in two or more ways, each of which are consistent with guilt.
2. In civil cases, when harm is shown to have resulted from one or more breaches of duty by a tortfeasor, and there is uncertainty as to which breach of duty caused the harm, it would be extremely unjust if plaintiffs were required to establish on the balance of probabilities which particular tortious act or acts resulted in the harm. It would be most unjust if a tortfeasor could escape liability as the result of a plaintiff being unable to discharge such a burden. A plaintiff might establish on the balance of probabilities that he had suffered damage as the result of a defendant's negligence, but recover no damages because there were two or more breaches of duty that could have caused the harm, and no individual breach of duty could be identified as causative. Furthermore, tortfeasors committing multiple distinct and varied breaches of duty would enjoy an advantage not shared by tortfeasors responsible only for single breaches of duty.
3. A number of the leading cases about causation in the law of negligence contain statements of principle which, at face value, might be taken to suggest that a plaintiff bears the burden of establishing causation by a particular breach of duty. For example, in Chappel v Hart (1998) 195 CLR 232 at [23], McHugh J said that "causation theory insists that the plaintiff prove that the injury is relevantly connected to the breach of duty". However such pronouncements should not be taken out of context and treated as authority in relation to a point of law that they were not intended to relate to.
4. As a matter of principle, if a plaintiff establishes on the balance of probabilities that a defendant owed him duties of care, and breached them, and that he suffered damage as a result of the plaintiff breaching such duties, then that plaintiff must be entitled to recover damages, even if it is not possible to establish on the balance of probabilities which breaches were causative. It follows that the learned trial judge was required to treat this case as a "strands in a cable" case, and to assess the combined strength of the possibilities that the appellant's damage had been caused by the various asserted breaches of duty on the part of the HEC and Aurora. By considering the evidence as to each asserted breach of duty in isolation from the evidence as to the other asserted breaches, his Honour erred in the manner asserted by ground 2 of the notice of appeal.
5. It does not follow that this appeal should necessarily succeed. Like Estcourt J, I take the view that the most appropriate course is for this Court to undertake its own assessment of the circumstantial evidence and reach a conclusion as to whether negligence has been established on the balance of probabilities. In deciding upon that course, I consider it very significant that the learned trial judge accepted that all the expert witnesses at the trial were honest and appropriately qualified. His only findings as to preferential evidence were based on some experts being more experienced than others.

The HV bushing to LV conductor flashover hypothesis

1. In simple terms, one of the transformer components carrying HV electricity on the pole was too close to one of the cables that carried LV electricity from the pole towards the appellant's premises.
2. The pole is connected to the appellant's premises by three cables. Two of them are designed to be live or "active". They are known as the "a" conductor and the "b" conductor. The third cable is the "earth" cable.
3. The position of the transformer on the pole is close to the "a" conductor and the "b" conductor. On the outside of the transformer there are two bushings. There are wires that connect each bushing to the overhead HV wires. HV electricity passes through each bushing. When transformers are installed on poles, it is important for the HV bushings and the LV conductors to be separated by a sufficient distance to avoid the risk of HV electricity flashing over from a bushing and entering the LV system.
4. The pole was installed by the HEC in 1987. The then applicable Australian Standard, AS2067-1984, in Table 9.1, specified a minimum clearance of 280 mm between an HV bushing and an LV conductor. In 1989 the HEC introduced a requirement that there be a minimum clearance of 310 mm. Subsequently another Australian Standard, AS2067-2008, introduced a requirement that there be a separation of 280 mm plus 15%. That amounts to 322 mm. In its amended statement of claim, the appellant pleaded that on 10 December 2010 the clearance was approximately 110 mm. That was admitted. At the trial, all the experts who gave evidence as to the point were in agreement that the actual clearance was less than the minimum safe clearance.
5. It must follow that the HEC breached its duty of care when it installed the pole in or around 1987 with too little separation between the bushing and the "a" conductor. Evidence at the trial established that employees of the HEC inspected the pole in September 1993 and December 1997, and that employees of Aurora inspected the pole in July 2001, February 2004, December 2006 and June 2010. The individuals carrying out each inspection either observed or ought to have observed the inadequate separation. Work should have been undertaken to obviate the risk of a flashover from the bushing to the "a" conductor. Aurora breached its duty of care by failing to undertake that work between 1 July 1998, when it took over from the HEC, and 10 December 2010.
6. As at that date there was no insulation on the "a" conductor. There was evidence at the trial that insulation was often installed on sections of such conductors adjacent to poles in order to obviate the risk of flashovers. In fact Aurora installed insulation on a short section of the "a" conductor adjacent to the pole in January 2012. The appellant did not plead that the HEC or Aurora was negligent in failing to install insulation on that conductor. However the absence of insulation on it means that the likelihood of a flashover from the HV bushing to it on 10 December 2010 was significantly greater than it otherwise would have been. That is a factor that weighs in the appellant's favour in the assessment of the strength of the circumstantial evidence.
7. As I have said, the learned trial judge made a finding, at [201], to the effect that it was possible that there had been a flashover from the bushing to the "a" conductor. That finding has not been challenged by the respondent. However there was evidence from the respondent's expert witnesses at the trial that they believed that no such flashover had occurred, for a number of reasons. It was said that a flashover would be likely to have left visible evidence of damage to the hardware on the pole, but no such visible evidence was found. It was said that such a flashover would have blown certain fuses located on the pole, but they did not blow. It was said that a power surge from such a flashover would have damaged electrical items in the house at the appellant's property, but not the PLC, which was further away from the pole, but there was no damage to items in the house and there was damage to the PLC. It was said that modelling of the likely consequences of the operation of the recloser at Glengarry, which was undertaken by suitably qualified experts including Dr Muthumuni showed that it was unlikely, at the least, that the result would be a power surge of sufficient strength and duration to reach and damage the PLC. All of those propositions will have to be considered when I assess the likelihood of the damage to the PLC having been caused in one or more of the ways relied upon by the appellant.

1. There are electrodes on the transformer that are known as spark gap rods or arc rods. Their purpose is to ensure that, in the event of an electrical surge, electricity is able to pass into the ground travelling along earth wires, to avoid the risk of damage to electrical appliances and/or individuals. Transformers are designed with spark gap rods positioned so that, in the event of a surge, electricity will arc across from one rod to another, and then continue along earth wires into the ground. The appellant contended that, as a result of negligence on the part of Aurora and the HEC, the spark gap rods on the pole were too far apart, and one of them was painted. The appellant contended that the paint made it less likely that electricity would pass from the painted rod as intended in the event of a power surge.
2. The design of the transformer appears in an HEC drawing numbered B12335 which was tendered on the trial. The transformer was designed to have arc gaps of 50 mm in series on the right and left sides on the pole. As at 10 December 2010, there was a separation of 65 mm in series on the left and a separation of 60 mm in series on the right. Those measurements were admitted on the pleadings. In these respects, the transformer was not constructed as designed. That failure created a risk that, in the event of a power surge, the arc rods would not do their job, and electricity would pass along an LV cable instead of going to earth.
3. It was admitted on the pleadings that the arc gap rods were covered in paint. There was no evidence of the thickness of the paint. The evidence suggested that the arc rods were painted by the supplier, not by the HEC or Aurora. The appellant led expert evidence that the paint would be likely to inhibit the operation of the arc gap rods in the event of a power surge.
4. I am satisfied that the HEC breached its duty of care by installing the transformer with arc gap rods that were incorrectly positioned. I need not make a finding as to whether the HEC or Aurora were negligent in failing to detect and rectify the incorrect positioning.
5. As I have said, the learned trial judge made a finding, at [203], to the effect that, because of the configuration of the spark gaps, there was a mechanism through which an HV surge could find its way to the LV "pathway". That finding has not been challenged in this appeal.
6. Again, the respondent relied on evidence from its expert witnesses that any flashover would be likely to have left visible evidence of damage to the hardware on the pole, that a power surge from any flashover would have damaged electrical items in the house rather than the PLC, and that modelling showed that it was unlikely, at the least, that there would have been a power surge of sufficient strength and duration to reach and damage the PLC.

1. The transformer had an earthing system. Two earth wires ran down the transformer and into the ground - an HV earth wire on one side of the pole, and an LV earth wire on the opposite side of the pole. The purpose of each earth wire was to transfer dangerous excess energy into the ground, where it could dissipate without causing any harm, in the event of a power surge or some other abnormal occurrence. The earthing system was designed so that HV electricity would not pass from the HV earth wire to the LV earth wire and enter the LV system. The appellant contends that that could have happened as a result of the earth wires not having been installed correctly in 1987, and the resistance between the HV and LV earth wires being too great as a result.
2. I am not satisfied on the balance of probabilities that the earth wires were installed incorrectly or negligently. However I am satisfied that there is a significant possibility that the earth wires were incorrectly positioned. The learned trial judge reached a similar conclusion at [191]. Although the evidence falls short of establishing negligence, I am satisfied that there is a significant possibility that the HEC breached its duty of care in 1987 by installing the earth wires in such a way that there remained a risk that, in the event of a power surge, electricity would pass from the HV earth wire into the LV earth wire, and on into the LV system. That could well have happened on 10 December 2010.
3. An HEC drawing showing the design of the pole, drawing B14731, specified that the maximum resistance of the earth connection between the HV earth and the LV earth was to be 30 ohms. Electricity will follow the path of least resistance. The higher the resistance, the less likely it is that electricity will dissipate into the ground, and the more likely it is that, in the event of a power surge, it will pass from the HV earth wire to the LV earth wire and into the LV system.
4. One of the respondent's witnesses, an experienced linesman named Stephen Doolan, gave evidence as to what was required in relation to the installation of earth wires at the foot of a pole with a transformer on it. HV and LV earth wires were usually installed on opposite sides of the pole, running down into the ground, and then running away from the pole at 180 degrees to one another. They were laid in trenches about 460 mm deep. They were required to be insulated near the pole, so that uninsulated wires were at least two metres from one another. Pins were driven into the earth at intervals of about one metre. Provided the ground was not too hard, they were driven in to a depth of six feet. The pins were connected to the earth wires. Readings were taken at each pin until a reading of 30 ohms or less was obtained.
5. Aurora replaced the HV and LV earthing systems in January 2012. A manager named Peter Burr oversaw that work. On 9 March 2012 he sent an email to various people in which he reported that testing results for the HV earthing system showed that its resistance before that work was undertaken was 97 ohms, and that its resistance after the work was done was 17.6 ohms. I infer that the first of those readings was taken either immediately before the replacement work commenced in January 2012, or shortly before that work commenced. At the trial, the appellant relied on that email as evidence that the earth wires must have been installed incorrectly and were unable to function as intended. However the learned trial judge observed at [174] and [175] that there was no evidence of the reading of 97 ohms being taken, nor of the method used to take it, that the reading was taken some considerable time after 10 December 2010, and that there was expert evidence that such a reading fluctuates as the resistivity of soil fluctuates. He concluded, at [175], "That evidence makes the applicability of the reading in 2012 to the actual reading (even the likely reading) in December 2010, uncertain at best."
6. In my view the evidence of the reading of 97 ohms deserves more weight than the learned trial judge gave to it. Mr Burr gave evidence at the trial as a witness for the respondent. No evidence was led by the respondent to suggest that the reading of 97 ohms was unreliable. It is clear from the evidence at the trial that resistance readings were routinely taken by competent Aurora employees. There is no reason to doubt that the resistance on the day the measurement was taken was about 97 ohms. That strongly suggests that the resistivity as at 10 December 2010 was well over 30 ohms, with the result that it was then likely that the earthing system would not have functioned as intended, and that HV electricity could have passed from the HV earth wire to the LV earth wire.
7. An internal Aurora document tendered on the trial revealed that, at least in the 2007/08 financial year, Aurora had a Statewide "Replace Transformer Earths Program" whereby work was undertaken to repair "pole mounted transformer earths that are found to have higher than permitted earthing values". The program involved routine audits of pole mounted transformer earths. It follows that there is not just a possibility of negligence on the part of the HEC in installing the earth wires in 1987, but also the possibility of negligence on the part of the HEC and Aurora in failing to detect a resistance far in excess of the required maximum of 30 ohms, and failing to undertake appropriate remedial work.
8. In 2016 the respondent arranged for an excavation to be carried out with a view to locating the original earth wires and establishing where they had been in December 2010. Sections of the original wires were exposed, photographed and filmed. However the evidence obtained by means of that excavation was inconclusive. Mr Doolan gave evidence to the effect that he noticed nothing untoward at the time of the installation of the new earth wires in 2012. Other witnesses who were involved in undertaking that work did not recall anything that strengthened the appellant's case.
9. As I have said, the learned trial judge made a finding at [191] to the effect that the passing of electricity from the HV earth wire to the LV earth wire as hypothesised was possible. That finding has not been challenged in this appeal. If electricity did pass from the HV earth wire to the LV earth wire as hypothesised, then that was a result of the HEC breaching its duty of care in 1987 by not installing the earth wires with a sufficient separation to achieve a resistance of 30 ohms or less.
10. The respondent's contentions as to the absence of visible evidence and the fact that fuses did not blow are not relevant to this hypothesis. However it relies on the opinions of its experts to the effect that it was unlikely that there would have been a power surge of sufficient strength and duration to reach and damage the PLC. It also contends that the reading of 97 ohms could have been caused or contributed to by excavations by the appellant in the vicinity of the pole and by natural changes in the resistivity of the soil. There was evidence that the appellant laid a PVC pipe below the surface of the soil near the pole in about 2003. There was no suggestion that the damage to the PLC in December 2010 was likely to have been caused or materially contributed by natural changes in the resistivity of the soil and/or changes in its resistivity resulting from the excavation to lay the PVC pipe. Further, I infer that the HEC and Aurora would have taken the possibility of natural changes in the resistivity of soils into account when choosing the figure of 30 ohms as the maximum allowable resistance.

1. A number of witnesses gave evidence about electrical breakdowns and outages over many years prior to 10 December 2010.
2. Mrs Sandra Hetherington gave evidence to the following effect. She worked at the site from 1986 until November 1992. At the beginning of that period the site was a new one. The electrical equipment was mostly new. She recalled a significant number of occasions when new electrical equipment broke down.
3. The appellant company was and is controlled by a couple named Karen Brock and Timothy Phillips. They were and are its directors. Ms Brock gave evidence of various pieces of electrical equipment breaking down or malfunctioning, including a brand new electric fence energiser, barcode printers, light globes, bread makers, roof vents in a green house, computers, a fax machine, a water steriliser, the PLC, and heaters. She said these electrical failures occurred from 1996 onwards, but that there had been no further electrical faults since 2012. Mr Phillips gave evidence similar to that of Ms Brock about a history of electrical failures.
4. There was evidence at the trial as to six identifiable occasions when electrical equipment of the appellant was damaged at times when the electricity supply from the pole was interrupted. The appellant complained to Aurora about damage to electrical equipment sustained on 15 July 2003. An Aurora employee subsequently wrote a letter confirming that there had been an interruption to the electricity supply to the appellant's nursery on that occasion as a result of the operation of a high voltage protection device at Clarence Point.
5. Aurora recorded an unplanned outage on 6 October 2009 from 8.46am to 5.37pm involving the recloser at Glengarry. The cause was recorded as "Vegetation Outside Clearance". Subsequently an Aurora employee recorded a complaint by Mr Phillips, described as follows: "Ongoing issues with supply. Had damage to equipment in house and nursery on 6 - 7 Oct 2009."
6. Mr Phillips recorded on a calendar that there was a "blip or outage" on 5 February 2010. In March 2010 he submitted a written claim to Aurora in respect of the damage to the appellant's equipment suffered on 6 October 2009 and 5 February 2010. There was evidence that on the second of those occasions the appellant suffered damage to computerised circuit boards and controllers, including a PC, a laptop, and an irrigation controller. Aurora paid the appellant over $4,000 in respect of that claim.
7. One of the respondent's expert witnesses, Mr Gillespie, mentioned in one of his reports that a PLC was allegedly damaged on the appellant's property on 24 April 2010. He reported that there was "an HV fault and recloser lockout causing an outage during windy weather".
8. In the same report, Mr Gillespie referred to a report of "damage to a computerised circuit board in a PC and UPS" occurring on or about 26 November 2011. He said that on that occasion there was an HV fault caused by a bird impacting a conductor, and that the recloser locked out causing an outage. That incident of course was after the outage of 10 December 2010, but it was before Aurora carried out any rectification work to the pole. I infer that Mr Gillespie's information as to that outage and the outage of 24 April 2010 came from Aurora's records.

1. Mr Phillips gave evidence that he turned off the potting machine at around 7pm on 9 December 2010, and next went to use it on 15 December 2010. He said he attempted to turn it on at 7am on that day, but that it would not start. He was unable to see what was wrong. He made a phone call, as a result of which an electrical technician named Paul Whiddon came to the property. Mr Whiddon inspected the PLC. He found the PLC to be correctly wired and installed. He measured the voltage provided to the electrical connections that powered the PLC and found it to be between 230 and 240 volts, which was the correct voltage. He opened the PLC, examined its internal circuitry, and saw shorting of some of the tracks around the communication tracks of the printed circuit board. He told Mr Phillips that a replacement was required. He subsequently installed a replacement PLC. The potting machine became operational again in February 2012. The damaged PLC was apparently disposed of.
2. The learned trial judge was provided with a statement of agreed facts which included the following:

"17 On 10 December 2010 the Defendant's recloser C690306 on Glengarry Road, which supplied 22kV electricity to the Pole, tripped four times and locked out at 23:38 hours.

1. The cause of the recloser operating was vegetation across the line at Flowery Gully approximately 6km from the recloser.
2. The operation of the recloser caused a loss of electricity to the Property. Electricity was restored at 2:58am on 11 December 2010."
3. Electricity from the pole went to part of the appellant's property, and not to any other property. On or about 10 December 2010, no harm was suffered to electrical equipment on the appellant's property that was not powered from the pole. There was no suggestion that any electrical harm was suffered on adjoining properties at that time. However the appellant had other electrical items, powered by electricity from the pole and closer to the pole than the PLC, that were damaged at the same time as the PLC. Mr Phillips found that a set of electronic scales and a transformer had become inoperable. He also found that a warning device supplied by Aurora called a Cable PI was flashing red.

1. In 2011 the appellant engaged an electrical engineer named Rayner Page to investigate the cause of the electrical failures at its nursery. Mr Page held a Master's degree and had about 18 years' professional experience at the time of the trial. His professional work had involved fault finding in both HV and LV systems, as well as work associated with microprocessor based electronics. He gave expert evidence at the trial for the appellant. Initially he believed that the cause of the failures would be located within the appellant's infrastructure. He undertook a detailed site assessment, made detailed tests of the appellant's electrical system, and concluded that its infrastructure complied with the relevant Australian Standard. He was unable to find any explanation for the electrical failures within the appellant's infrastructure, and therefore turned his attention to Aurora's infrastructure. He noticed that the right hand bushing on the transformer was too close to the "a" conductor, and that the spark gaps on the transformer were not correctly aligned. He also noticed that the spark electrodes were painted.

1. The appellant called three expert witnesses at the trial - Mr Page, Mr Piper and Mr Johnston. Mr Piper is an electrical engineer who graduated in 2011 and had about seven years' professional experience at the time of the trial. He had experience in project engineering that included arc flash hazard analysis work for power stations and distribution networks, as well as the design and testing of earthing systems for sites that included power generation, transmission, distribution, mining and industrial sites. Mr Johnston is another electrical engineer. He had some 10 years' professional experience at the time of the trial, including experience in relation to power and lightning surge protection, and the design and testing of earthing systems.
2. None of the parties' expert witnesses had ever seen the PLC, but four photos were tendered that showed it in its damaged state. On the basis of the damage that they saw in those photographs, Mr Page and Mr Piper both opined that the harm to the PLC was caused by a surge. Mr Johnston gave evidence that the damage seen in the photographs appeared to be only to the terminals of the device. He opined that one would expect to see damage to other components if the damage had been caused by an under voltage.

1. In the first half of 2012 employees of Aurora did three very significant things:
   • In early or mid-January 2012 they installed the insulation that I have referred to on a section of the "a" conductor adjacent to the pole.
   • On 20 January 2012 they replaced the HV and LV earthing systems at the base of the pole. The new earth wires were installed as the old ones should have been, running away from one another at an angle of 180 degrees, with insulation on the sections adjacent to the pole. After their installation the relevant resistance was measured at 21 ohms.
   • On 27 June 2012 they raised the transformer to a higher position on the pole, thus adequately separating the HV bushings from the LV "a" conductor.
2. Ever since the insulation was fitted in January 2012, the replacement PLC has operated satisfactorily and the appellant has suffered no further electrical harm. In my view that is an extremely significant piece of circumstantial evidence.

1. The respondent's principal expert witnesses at the trial were Mr Gillespie and Dr D'Alessandro. Mr Gillespie is an electrical engineer who graduated in 1979. At the time of the trial he had over 30 years' professional experience. He had worked as an independent specialist consultant since 2010, had published dozens of technical papers, and was an experienced expert witness. Dr D'Alessandro is a former academic. After moving into the private sector his work included lightning protection work as a senior research scientist, and work as a research and development product engineer. He has worked as an independent consultant since 2007 in relation to lightning protection and earthing projects. He has published many technical papers and spoken widely at seminars and conferences.

1. The respondent's witnesses at the trial included two experienced linesmen, Mr Reeves and Mr Jarman. Mr Reeves gave evidence that on occasions he had attended places where HV and LV conductors had been in contact. He said he had observed conductors that were burnt, splattered and melted. Mr Jarman gave evidence that he inspected the transformer in 2017. He deduced that its original components had not been replaced. In his proof of evidence, which was tendered, he said this:

"I did not see, and the photos don't show, any burn marks or burning on the metal on the transformer or on the conductors. If there had been a flashover at this pole, I would expect from my experience to have seen burn marks or melting on at least some of the metal and possibly discolouration of the porcelain on the bushings. I saw only what I regard as normal wear and tear."

1. Mr Gillespie stated his opinion as to this issue in one of his reports, as follows:

"... I say that if a switching surge flashed over between the HV bushing and LV conductor 'a', then I would expect a power follow current. Heat from power follow current would melt some of the metal on both the HV and LV conductors. Pitting due to melting of the surface would be visible to the naked eye similar to the mark on the rod of the spark gap. Initially it would be shiny but may become dull over time. I would expect it to be clearly visible seven years later."

1. However Mr Piper's opinion was that a flashover from the HV bushing to the LV conductor caused by a surge might not cause any mark at all. Mr Page commented that it was evident from photographs that the spark gaps on the pole had fired and operated at some point in time, but that it was not possible to determine when they fired or how many times they had fired.
2. The learned trial judge observed, at [201], that the lack of any visible evidence of a flashover event might be explained by the passing of time, but might also suggest that there was no such event. Mr Page's observation suggests that there was visible evidence of a flashover. If there was no such evidence, that would be a factor weighing in favour of the respondent, but in my view it would be a very minor factor.

1. There were fuses on the pole, but none of those fuses blew on 10 December 2010. That is common ground. In Mr Gillespie's opinion, if there had been a flashover from the spark gaps to the HV earth a fuse would have blown.
2. However Mr Piper took the view that, because of the speed of a surge event, the surge would pass through the fuses without them getting hot enough to blow. Mr Page adopted Mr Piper's opinion as a correct opinion.
3. The learned trial judge considered the evidence about the fuses in isolation, and concluded, at [229], that he preferred the evidence of Mr Gillespie. At [208], his Honour said that he preferred the evidence of Mr Gillespie over that of Mr Page and Mr Piper because of his qualifications and experience, and because his evidence was consistent with modelling evidence adduced by the respondent. In my view it is not appropriate to make findings as to issues on which the expert witnesses in this case have disagreed without considering the evidence as a whole. If the respondent's case was supported by expert opinion evidence from the best qualified expert in relation to the fuses, that is certainly a factor that weighs in favour of the respondent, but that expert's opinion is no more than an opinion, and opinions can be incorrect.

1. Calculations as to the voltages and currents on the appellant's property resulting from a hypothetical flashover event were undertaken by Mr Gillespie, and Dr D'Alessandro. The respondent also relied on Dr Muthumuni's report, which contained calculations as to voltages and currents based on several modelling scenarios.
2. Mr Gillespie opined that a surge affecting the HV system would have produced a voltage of no more than 55 kV, and that a voltage of 98 kV would have been required for there to have been a flashover from the HV bushing to the LV conductor "a". Further, he opined that if such a flashover had occurred, the largest magnitude of the surge would have occurred at the house, and that the surge would have been attenuated as it travelled onwards to the PLC. If so, electrical equipment between the pole and the PLC would be expected to fail but it did not, hence his conclusion that the PLC's failure was not due to a surge.
3. Dr D'Alessandro opined that the voltages reaching the potting shed would have been well below 1,000 volts, and that a surge of up to 1,392 volts was unlikely to have caused any damage to the PLC.
4. Dr Muthumuni's report was dated 17 May 2018. That report was written some two months after the trial started. The trial ran for nine days commencing on 13 March 2018, continued on 16 April, and resumed on 22 May. On that day counsel for the respondent sought to adduce Dr Muthumuni's evidence, but counsel for the appellant objected on the basis that the late delivery of the report caused prejudice. It was conceded that the report was an authentic document and that its contents were relevant. Counsel for the appellant made it clear that if evidence of Dr Muthumuni's opinions was to be admitted over their objection, then the report could be tendered instead of Dr Muthumuni having to give oral evidence. The learned trial judge rejected the objection but offered the appellant an adjournment to deal with the prejudice said to have been caused by the late delivery of the report. That offer was declined by senior counsel for the appellant, who had said that his client did not have the resources to continue the trial beyond that week. The report was tendered as an exhibit and Dr Muthumuni was not called as a witness.
5. Ground 15(a) of the notice of appeal asserts that the learned trial judge erred in admitting the evidence of Dr Muthumuni. In my view that ground should fail. The learned trial judge discharged his duty to afford the appellant procedural fairness by offering it an adjournment. It cannot be said that the decision to admit the report and offer an adjournment was "unreasonable or plainly unjust": House v The King (1936) 55 CLR 499 at 505.
6. It is therefore appropriate that this Court should take the report of Dr Muthumuni into account. In deciding what weight to attach to his report, it is significant that he was not called as a witness, and that his opinions were therefore not tested by cross-examination. At the trial, counsel for the appellant made many criticisms of Dr Muthumuni's report. The learned trial judge listed 15 submissions made by them in his reasons at [244]. That paragraph is reproduced in the judgment of Estcourt J.
7. Dr Muthumuni is an eminent expert. He undertook modelling and calculations in relation to the three hypotheses that I have described above. Those that I have referred to as the HV bushing to LV conductor flashover hypothesis and the earth wires hypothesis both assumed that the spark gaps had flashed over. However Dr Muthumuni concluded that it was "unlikely that the amplitude of the surge voltage would be sufficient for the air gaps to flashover". As to the spark gap hypothesis, the only conclusion expressed by Dr Muthumuni was that the maximum voltage recorded across the HV bushing air gap was 36.73 kV.
8. The contents of Dr Muthumuni's report were used by Dr D'Alessandro to review the conclusions that he had reached. He performed various calculations, and adhered to his earlier conclusions that there was insufficient voltage for the PLC to have been damaged by any of the mechanisms suggested by the appellant's experts, and that it was unlikely to have been damaged by a switching surge.
9. Modelling was also undertaken by Mr Johnston. He disagreed with Dr D'Alessandro as to some points, and there were some matters of detail in Dr D'Alessandro's evidence on which he expressed no opinion due to a lack of specialised expertise.
10. The modelling undertaken by the expert witnesses involved some very sophisticated calculations. Those calculations involved many variables. Many assumptions were made. The modelling and calculations undertaken by Dr Muthumuni and Dr D'Alessandro certainly showed that damage to the PLC was not a result that they would have expected following the recloser event on the night of 10 December 2010. However their work did not produce evidence that such a result was impossible. Despite their impressive qualifications and experience, one could not rule out the possibility that one or more of their assumptions were inaccurate, nor the possibility that there was some factor that they had not taken into account.

1. Although the respondent's principal expert witnesses may have more impressive credentials than those of the appellant, this is very much a case in which conflicting opinions were expressed by appropriately qualified experts. Generally speaking, the evidence of the respondent's experts was to the effect that the causing of damage to the PLC in each of the three ways hypothesised by the appellant was unlikely, but possible.
2. In assessing the strength of the appellant's case, this Court is required to take into account all the relevant circumstantial evidence. That evidence includes the evidence of electrical breakdowns and outages on the appellant's property, the evidence that such events ceased after the work undertaken by Aurora in early 2012, and the evidence that Mr Page sought and did not find anything on the appellant's property or in its infrastructure that could possibly have caused the failure of the PLC.
3. It is also significant that the respondent's experts have not identified any cause for the failure of the PLC. Of course the respondent does not bear an onus of proof. But it is hardly likely that something unknown went wrong with the appellant's equipment or infrastructure at around the time of the recloser event in December 2010, was not later detected by Mr Page, and did not go wrong again.
4. Having regard to all the relevant facts and circumstances, I am satisfied on the balance of probabilities that the damage to the PLC and any consequential damage suffered by the appellant was caused by HV electricity entering the LV system in at least one of the three ways hypothesised by the appellant. However the evidence falls short of establishing on the balance of probabilities that the HV entered the LV system in any particular one of those ways.
5. On that basis I am satisfied on the balance of probabilities that the damage was caused by one or more breaches of duty for which the respondent is responsible, but I am not satisfied on the balance of probabilities that the damage was caused by any particular breach of duty.

Section 13(2) of the Civil Liability Act 2002

1. Counsel for the appellant relied on s 13(2) of the Civil Liability Act. Section 13 reads as follows:

"13(1) Prerequisites for a decision that a breach of duty caused particular harm are as follows:

(a) the breach of duty was a necessary element of the occurrence of the harm ('factual causation');

(b) it is appropriate for the scope of the liability of the person in breach to extend to the harm so caused ('scope of liability').

(2) In deciding in an exceptional case, in accordance with established principles, whether a breach of duty, being a breach of duty that is established but which can not be established as satisfying subsection (1)(a), should be taken as satisfying subsection (1)(a), the court is to consider (among other relevant things) whether or not and why responsibility for the harm should be imposed on the party in breach.

(3) If it is relevant to deciding factual causation to decide what the person who suffered harm would have done if the person who was in breach of the duty had not been so in breach -

(a) the matter is to be decided subjectively in the light of all relevant circumstances, subject to paragraph (b); and

(b) any statement made by the person after suffering the harm about what he or she would have done is inadmissible except to the extent (if any) that the statement is against his or her interest.

(4) For the purpose of deciding the scope of liability, the court is to consider (among other relevant things) whether or not and why responsibility for the harm should be imposed on the party who was in breach of the duty."

1. The appellant contends that this is an exceptional case to which s 13(2) applies.
2. Section 13(2) was enacted following recommendations made to the Commonwealth Government in the "Ipp Report" - Review of the Law of Negligence Final Report (September 2002). In that report at [7.32], the authors expressed the view that it would be widely considered to be fair and reasonable to bridge evidentiary gaps in certain types of cases. Section 13(2) was enacted for the purpose of bridging such evidentiary gaps. The authors of the report identified two types of evidentiary gaps. The first was described as follows at [7.28]:

"7.28 One involves harm which is brought about by the cumulative operation of two or more factors, but which is indivisible in the sense that it is not possible to determine the relative contribution of the various factors for the total harm suffered. This was the situation in the English case of Bonnington Casting v Wardlaw [[1956] AC 613], which lays down the principle that any of the contributory factors can be treated as a cause of the total harm suffered, provided it may a 'material contribution' to the harm. The effect of this rule is that a defendant may be liable the total harm suffered by a plaintiff even though it cannot be said that, but for the conduct of the defendant, the plaintiff would not have suffered the total harm; and that it can only be said that but for the conduct of the defendant the plaintiff would not have suffered some of that harm."

1. The authors described the second type of evidentiary gap as follows at [7.30]:

"7.30 A recent illustration of the second type of case in which an evidentiary gap may exist is provided by the decision of the English House of Lords in Fairchild v Glenhaven Funeral Services Ltd [2002] UKHL 22; [2002] 3 WLR 89. The plaintiffs contracted mesothelioma as a result of successive periods of exposure to asbestos while working for different employers. The scientific evidence about the aetiology of mesothelioma did not justify a conclusion, in relation to any of the plaintiffs' employers, that but for the negligence of that employer, the plaintiffs would not have contracted the disease. The court held that in such a case, proof (on the balance of probabilities) that the defendant's negligent conduct 'materially increased the risk' that the plaintiffs would contract mesothelioma, would suffice to establish a causal connection between the conduct and the harm."

1. In a sense there is an evidentiary gap in this case, in that the evidence establishes on the balance of probabilities that the harm suffered by the appellant was caused by one or more breaches of duty on the part of the respondent's predecessor, for whose torts it is liable, but does not establish on the balance of probabilities that that harm was caused or contributed to by any particular breach of duty. That is not the sort of evidentiary gap that was identified in the Ipp Report. It is not the sort of evidentiary gap that s 13(2) was intended to address.
2. From one perspective, the appellant does not need to rely on s 13(2). Its case does not depend upon establishing that in the words of s 13(1), "a breach of duty caused particular harm". It contends that there were more than one breaches of duty, and that the evidence establishes on the balance of probabilities that its harm was caused by at least one breach of duty for which the respondent is liable. If that results in the respondent being liable to pay damages, there is no need for any particular breach of duty to be taken, pursuant to s 13(2), as satisfying s 13(1)(a).
3. If I am wrong as to that, and responsibility for the appellant's harm cannot be imposed upon the respondent without reliance upon s 13(2), then there is every reason why it should be, even though this case involves an evidentiary gap of a third kind that was not contemplated by the authors of the Ipp Report. The words of s 13(2) should be given their ordinary literal meaning: Project Blue Sky Inc v Australian Broadcasting Authority (1998) 194 CLR 355 at [78]; Alcan (NT) Alumina Pty Ltd v Commissioner of Territory Revenue [2009] HCA 41, 239 CLR 27 at [47]. Breaches of duty have been established in relation to the installation of the pole without an adequate separation between the right hand bushing and the "a" conductor, and with inappropriate spark gap separations, and in the failure to rectify the first of those defects over many years. The evidence establishes on the balance of probabilities that the appellant's harm was caused by negligence for which the respondent is liable, but one possibility is that it was caused by the negligent installation of the HV and LV earth wires - a possible breach of duty that is not established on the balance of probabilities. In those circumstances it would be unreasonable and unjust for responsibility for the harm not to be imposed upon the respondent.

1. It follows that the appeal must succeed, that there must be judgment for the appellant, and that there must be an assessment of damages.

1. At the hearing of the appeal, counsel for the respondent submitted that, in the event of the appeal succeeding, any assessment of damages should be undertaken by the learned trial judge. The trial was not limited to liability. His Honour received all the evidence that the parties wished to present in relation to damages, together with detailed submissions as to that evidence.
2. Counsel for the appellant submitted that any assessment of damages should be undertaken by either a different judge or the associate judge. Counsel informed the Court that the learned trial judge had made orders as to costs before the hearing of the appeal, and had received information as to offers of settlement or compromise during argument as to costs. We were given no details of the amounts offered, the terms of any offer, or even whether offers were made by both parties or just one party.
3. There is no general rule that a judge becomes disqualified from determining a matter upon receiving details of an offer of settlement or compromise, or of a payment into court. In such a situation, a judge ordinarily has a discretion to continue with a case or not to do so: Harvey v Harvey [1965] QWN 41; Murphy v Murphy [1963] VicRp 83; [1963] VR 610; Skafidas v ATM Industries Pty Ltd [1979] VicRp 16; [1979] VR 164; Williams v Volta [1982] VicRp 74; [1982] VR 739; Bullhead Pty Ltd v Brickmakers Place Pty Ltd (No 2) [2019] VSCA 7. It appears from Murphy v Murphy that it is open to a judge to abort a hearing after learning of a payment into court either to avoid embarrassment, or to ensure that justice is seen to be done.
4. If this matter were remitted to the learned trial judge for him to assess the appellant's damages, and if he were to make an award that was less favourable to the appellant than a settlement or compromise known by him to have been offered to it or by it, justice might not be seen to be done. I do not see this as a case where a fair-minded lay observer might at this stage reasonably apprehend that his Honour might not bring an impartial mind to the assessment of damages. He would be disqualified if that were the case: Ebner v Official Trustee in Bankruptcy [2000] HCA 63, 205 CLR 337. Nevertheless, I think that this is an appropriate case for the Full Court to exercise its discretion by requiring the assessment of damages to be undertaken by another judicial officer, despite the cost and delay that are likely to result.
5. It is not practicable for the assessment of damages to be undertaken by the Full Court since none of the evidence relating to the quantum of damages has been relevant to the grounds of appeal. The only appropriate course is for the assessment of damages to be undertaken by a single judicial officer - either the associate judge or a judge other than the learned trial judge. It is appropriate that the choice of the judicial officer to undertake the assessment of damages be made administratively.

1. For these reasons I would allow the appeal, set aside the judgment for the respondent and the orders of the learned trial judge as to costs, order that judgment be entered for the appellant against the respondent for damages to be assessed, and order that the damages be assessed by a judicial officer other than the learned trial judge.

BROCKLANDS PTY LTD v TASMANIAN NETWORKS PTY LTD

1. The appellant company, Brocklands Pty Ltd, has appealed to this Court against an order made by the learned trial judge, Geason J, on 28 June 2019, dismissing the appellant's action for damages against the respondent in Brocklands Pty Ltd v Tasmanian Networks Pty Ltd [2019] TASSC 26.
2. The appeal is brought on two primary grounds, as follows:

"1 The learned trial judge erred at in deciding that the Plaintiff had not pleaded a case in negligence and as a consequence failed to consider the Plaintiff's case in negligence.

1. The learned trial judge erred in failing to consider and decide the circumstantial case put by the Plaintiff as he did not consider the weight to be given to the united force of all the circumstances put together."
2. Other paragraphs in the notice of appeal listing "Errors in Fact Finding", numbered 1 to 9 and "Errors as to Evidence", numbered 10 to 16, assert, in effect, that the evidence, correctly assessed, compels a conclusion that the appellant is entitled to judgment.

1. Since 1996 the appellant has operated the Brocklands nursery on a property at Winkleigh in northern Tasmania, known as Markfield. The company produces roses, ornamental plants and berries, and supplies them to commercial markets. It purchases electricity from Aurora Energy (Aurora), which is delivered from the respondent's infrastructure in the Launceston suburb of Trevallyn, to Markfield, over the respondent's network, utilising the respondent's poles and wires.
2. High voltage power travels from Trevallyn, for about 14 kilometres, along two high voltage lines, until it reaches a pole located at Markfield (the pole). The pole was installed in 1987 by the then Hydro Electric Commission, and it forms part of the distribution network for which the respondent subsequently assumed legal responsibility. It is identified as pole number 343836. The pole supplied the appellant's property and did not supply any other person's property.
3. When the pole was erected, a transformer, identified as number T690640, was installed on it. The pole and the equipment connected to it have never been replaced although, importantly, their configuration was modified after the contested events of 10 December 2010. The transformer was purchased, in the condition in which it was installed, from a manufacturer, Machinery Construction (Heidelberg) Pty Ltd.
4. The function of the transformer is to convert 22,000v high voltage electricity to 230v or 240v low voltage electricity suitable to power a household. Two cables arrive at the pole from the power station in Trevallyn. They deliver high voltage electricity, and are referred to as the "Active A" and "Active B" lines. At the pole they pass through the transformer, from which low voltage electricity emerges. Three low voltage cables leave the transformer and go to the main premises at Markfield, including the nursery, but not the pump shed. These low voltage cables are referred to as the "Active a", "Active b" and "Neutral" lines.
5. On 10 December 2010 a branch from a tree fell across the high voltage power line some way away from Markfield and as a result a "recloser" tripped at Glengarry, about six kilometres away, on the Trevallyn side of Markfield. A recloser is a circuit breaker which cuts off the power and then switches it back on again in an endeavour to clear the line. The recloser tripped four times on 10 December 2010 before locking out, having failed, for obvious reason, to clear the obstruction. Thereafter a work crew was dispatched to remove the tree and manually turn the power back on.
6. The appellant's case at trial was a circumstantial one, namely that the operation of the recloser generated a power surge, which could have been between two and five times the normal operating voltage of the line, and that the surge passed through the high voltage conductors and headed towards the pole, where high voltage electricity was able to enter the low voltage system because the equipment on the pole was either defective and/or incorrectly installed. The appellant's action arose as a result of asserted surge damage sustained by the programmable logic controller (the PLC) of a potting machine utilised in its nursery business. A programmable logic controller is merely an industrial digital computer which has been "ruggedized" and adapted for the control of manufacturing processes, such as assembly lines, or robotic devices, or any activity that requires high reliability control and ease of programming and process fault diagnosis.
7. The potting machine was purchased in October 2009 when the appellant's directors decided to automate the potting process. The company purchased a "Demtech" brand potting machine able to automatically transfer small plants into pots. The potting machine worked with a Mitsubishi FX2N PLC.
8. The appellant's case was that the surge of electricity exceeded the "dielectric withstand voltage range" of the PLC. All electrical equipment has such a range. As the name suggests, it represents the capacity of an electrical device to withstand a maximum voltage for a specified period of time. Operation outside the withstand voltage range for longer than the specified period is expected to result in damage to the equipment. The potting machine was engineered to have a dielectric withstand voltage range which tolerated 500 volts for one minute. As will be seen, questions arose at trial as to whether a single surge or multiple surges of less than 500 volts, or for less than one minute, would damage the PLC in the way in which it was.

1. As noted, ground 1 of the notice of appeal asserts that:

"The learned trial judge erred in deciding that the Plaintiff had not pleaded a case in negligence and as a consequence failed to consider the Plaintiff's case in negligence."

1. His Honour's analysis of this issue appears at [61]-[77] of his reasons for judgment as follows:

"[61] If negligence is pleaded, the question of whether the defendant is susceptible to an action in negligence arises as a preliminary issue. Relevant to that question is Graham Barclay Oysters Pty Ltd v Ryan [2002] HCA 54, 211 CLR 540 [8] (Gleeson CJ); Vairy v Wyong Shire Council [2005] HCA 62, 223 CLR 422 [59]‑[60] (Gummow J). The issue can be a complex one, indicative of the need for a carefully articulated plea to the effect that the common law duty is engaged. In the joint judgment of Gummow and Hayne JJ in Graham Barclay Oysters (above) at 596-597:

'[146] The existence or otherwise of a common law duty of care allegedly owed by statutory authority turns on a close examination of the terms, scope and purpose of the relevant statutory regime. The question is whether that regime erects or facilitates a relationship between the authority and a class of persons that, in all the circumstances, displays sufficient characteristics answering the criteria for intervention by the tort of negligence.'

[62] Before that issue is required to be considered, there is a threshold matter raised by the defendant relating to the pleadings.

[63] That issue arose in this way. In closing the defendant submitted that the plaintiff had failed to plead a breach of any common law duty. Indeed the defendant says that it was not until the plaintiff's opening address that it was aware that any common law duty was alleged to have been breached. Senior counsel for the defendant, Mr McTaggart SC, said that 'it is the first time in approximately five years of litigation that such a duty has been alleged, notwithstanding that there have been three amendments to the statement of claim ...'.

[64] It was only in closing that senior counsel for the plaintiff, Mr Reid (sic) SC, identified the basis for a common law duty, when he said 'this is not a novel duty case and falls within the Donoghue v Stevenson type of duty category regarding the provision of products and services for valuable consideration'. The plaintiff submitted that the defendant was aware of the common law action at least at the time the plaintiff opened its case. At no time during the trial has there been an application to amend the pleadings in this respect.

[65] The defendant's contention is that an action in negligence is not pleaded. It further submits that the case does not fall within an established category of duty, because the plaintiff did not pay for the installation or maintenance of the pole, and the defendant has never been a retailer of electricity to the plaintiff. The distribution business for which it assumed responsibility (and exposure to liability) is defined in the transfer notices (1988 and 2014) to mean the activities relating to or associated with the distribution of electricity, including construction, maintenance and operation of that network. Since the disaggregation of the electricity industry, the defendant has not engaged in the retailing of electricity and, as recorded elsewhere, it has not assumed legal responsibility for damage arising from that activity by those entities.

[66] It is of course the pleadings which are determinative of the claim, not counsel's submissions. The pleadings are for the parties to determine, not the court; the court will deal with an application to amend or strike out the pleadings if it is made. It will not otherwise involve itself in their content. The pleadings must state the material facts and any statutory or regulatory provisions relied upon, identify the issues required to be resolved and the relief claimed. Rule 227 of the Supreme Court Rules 2000 requires that pleadings are to give 'reasonably explicit notice to any other party of all grounds of action or all defences on which the party pleading intends to rely at the trial'. I am aware of the decision of Blow J (as he then was) in Jones v Clyde Welshpool Pty Ltd (2009) 9 Tas R 391; [2000] TASSC 130, on an interlocutory application to strike out an action for failing to plead a duty. Neither party referred me to this case, but different considerations apply in that context. It predates the CLA [Civil Liability Act 2002] which in my view requires a pleading to address its elements, including the duty, and the scope of the duty. If the Supreme Court Rules are silent as to such a requirement I do not think it follows that a pleading which ignores the issue survives curial scrutiny, as if the authorities on the matter did not exist.

[67] The importance of pleadings as a foundation for procedural fairness was observed in Banque Commerciale SA v Akhill Holdings (1990) 169 CLR 279 at 286 by Mason CJ and Gaudron J who reiterated that the function of pleadings is to state with sufficient clarity the case which must be met. This ensures that a party understands the case put against it and can frame its response.

[68] This principle is subject to the qualification that if the parties run the case on a different basis it should be decided on that basis: Banque Commerciale SA (above). That course requires the acquiescence of the defendant in the conduct of the action on such different basis. The defendant has taken this point since it emerged at trial. There is no interpretation of its conduct of the proceedings that could be construed as acquiescence in an action in negligence.

[69] Turning to the pleadings, at par 18 of the statement of claim (above) the plaintiff alleges that each of the matters pleaded as a breach of the relevant statutory duty constituted a 'negligent breach of duty'. This is followed by 'Particulars of negligence'. The plaintiff submits that this is a pleading of an action in negligence. It says that since a breach of statutory duty does not include any element of negligence, the articulation of the claim in terms of negligent breach of duty necessarily pleads an action in negligence, arising from the same factual circumstances.

[70] The defendant described this is an invitation to imply a cause of action not otherwise pleaded.

[71] As a matter of language and sentence structure, 'negligent' is used in par 18 as an adverb qualifying the word 'breach', the breach being a reference to the alleged departures from the statutory duty set out in the preceding paragraphs.

[72] The pleadings omit a statement, explicitly pleaded or by reference to some other aspect of the pleadings, of the legal relationship relied upon for the purposes of establishing a duty of care at common law. A duty of care is a particular and defined legal obligation arising out of a relationship between plaintiff and defendant; Roads and Traffic Authority of NSW v Dederer [2007] 234 CLR 330; at [44] per Gummow J.

[73] An assessment of breach of duty requires an answer to the anterior question of the nature of the duty of care. The importance of the relationship and, in turn, its relevance to the content of the duty is evident in cases such as CAL No 14 Pty Ltd v Motor Accidents Insurance Board [2009] HCA 47, 239 CLR 390. The existence of a statutory duty can never be a sufficient basis on its own for the creation of a common law duty of care. There will always be some other element, such as obligations flowing from a relationship between the parties; Sutherland Shire Council v Heyman [1985] HCA 41; (1985) 157 CLR 424, 459-60, 463 (Mason J); Stovin [1996] UKHL 15; [1996] AC 923, 935 (Lord Nicholls); Crimmins v Stevedoring Industry [1999] HCA 59, 200 CLR 1, 60-61 (Gummow J).

[74] Whilst the statutory obligations pleaded can simultaneously inform the content of the defendant's common law obligations (which must be met to satisfy the duty of care), merely adding the label 'negligent' does not elevate a reference to them, to the pleading of an action in negligence.

[75] In the circumstances, the defendant quite properly asks 'is the plaintiff relying upon an established duty or a novel one?' The pleadings should say. It should not be left to a closing submission as it was by the plaintiff.

[76] As Kirby J observed in Romeo v Conservation Commission (NT) (1998) 192 CLR 431 at [122]:

'It is one thing to hold that a person owes a duty of care of some kind to another. But the critical question is commonly the measure or scope of that duty. The failure to distinguish these concepts can only lead to confusion'.

[77] I conclude that no action for negligence at common law is pleaded. I uphold the defendant's submissions."

1. I am of the respectful opinion that the learned trial judge erred in concluding that no action for negligence was pleaded.
2. The endorsement of claim on the appellant's writ expresses the action to be for "breach of contract and or breach of duty of care and/or breach of statutory warranties ...". (Emphasis added.)
3. No express claim for breach of "statutory warranty" was pleaded in the amended statement of claim on which the trial was conducted. Nor was any claim for breach of statutory duty expressly pleaded in that document. Indeed it may not have been open to the appellant to have done so, unless such a private cause of action was embraced by the words "breach of duty of care" in the endorsement of claim.
4. In Renowden v McMullen [1970] HCA 24; (1970) 123 CLR 584, Barwick CJ and McTiernan J, dissenting as to the outcome, observed at 595:

"The indorsement on the writ not being a statement of claim is not in the nature of a pleading. In our opinion, it should not be construed as such but read for what it is, namely, a notice of the nature of the plaintiff's claim, of the cause thereof and of the relief sought in the action. It suffices if it conveys that information generally and without particularity save where and to the extent to which particularity is indispensable to notify the required elements of the indorsement, eg on some occasions identification of the instrument upon which a claim is founded. But insufficiency of the indorsement does not render the writ a nullity. Hill v Luton Corporation (1951) 2 KB 387; Pontin v Wood (1962) 1 QB 594. On the other hand, the indorsement marks out the perimeter or range of the area within which the plaintiff may express his claim in a formal fashion in his statement of claim whether as originally filed or as sought to be amended see Cave v Crew (1893) 62 LJ Ch 530, United Telephone Co v Tasker (1888) 59 LT 852, Moore v Alwill (1881) 8 LR Ir (CL) 245; 15 Ir LT 45, at p55 'The statement of claim is the specific way of stating the claim he has endorsed on the writ' per Dowse B in Moore v Alwill (1881) 8 LR Ir (CL) 245; 15 Ir LT 45, at p55 (at p595)." (Emphasis added.)

1. In any event, no point was taken when a claim for breach of statutory duty was in fact expressly pleaded in the original statement of claim, along with a clear claim in negligence. As senior counsel for the appellant, Mr Read SC, noted in his written closing address at trial:

"Senior Counsel's assertion that the Plaintiff's opening is the first time in five years that a duty in negligence is alleged is patently incorrect. In the Plaintiff's first Statement of Claim filed 3 August 2015 at paragraph 13 the Plaintiff pleads as follows: 'the high voltage flashovers that caused damage to the plaintiff's property occurred as a result of negligence and breach of statutory duty on the part of Aurora Energy Pty Ltd.' The Statement of Claim goes on at paragraph 15 to reiterate 'as a result of Aurora Energy Pty Ltd's negligence and breach of its statutory duties, the plaintiff has suffered loss and damage and has been put to expense.'

The Plaintiff filed an Amended Statement of Claim on 9 November 2016. The Amended Statement of Claim contained paragraph 18 in identical terms and has remained therein until the present version of the Statement of Claim."

1. Paragraph 18 of the appellant's amended statement of claim at trial (being that filed on 23 March 2018), clearly pleaded a "negligent breach of duty" and set out "Particulars of Negligence". The pleading may be inelegant but it plainly connotes a claim in negligence - which of course is a claim for a "breach of duty of care". The statement of claim pleads facts going to duty, breach, factual causation and damage.
2. In view of the terms of par 18 and the particulars of negligence thereunder, maintained from the original statement of claim across to the amended statement of claim at trial, the pleading could not in my view have been properly regarded as abandoning the earlier expressly pleaded claim that the appellant's damage was caused by the respondent's negligence. On the contrary, having regard to the amendments to the original statement of claim, if anything was abandoned, it was arguably the specifically pleaded breach of statutory duty. While the word "negligent" appears three times in the amended pleading, and the word "negligence" once, the words "statutory duty" do not appear at all.
3. Further, the particulars of negligence in the amended statement of claim included references to matters which may have amounted to a breach of a statute, but they are plainly enough asserted as negligent breaches of duty. That is to say, breaches of a duty of care, not negligent breaches of a statutory duty. That is perfectly orthodox in my opinion and does not somehow transform a claim in negligence into one for breach of statutory duty.
4. As senior counsel for the appellant, Mr Read SC submitted at trial, a breach of statutory duty does not include (I suggest, require), any element of negligence, but the articulation of the claim in terms of a negligent breach of duty sufficiently pleads an action in negligence.
5. Moreover, there are breaches of standards and codes as pleaded in the amended statement of claim which cannot sensibly be understood as founding claims for breach of statutory duty, yet they are clearly pleaded as particulars of negligence. Other particulars of negligence are quite unrelated to any specific breach of statute or standard or code, thus resting in negligence only, for example, particular (i) of par 18 - " Failure to identify and/or report and/or prioritise and/or attend to the defects referred to in paragraph 18 (i) of this Statement of Claim."
6. It will be recalled that on 1 July 2014, pursuant to the Electricity Reform Act 2012, all the assets, rights, and liabilities in Aurora Energy Pty Ltd's distribution business were transferred to the respondent. Thereupon the respondent was responsible for liabilities arising from damage caused by the distribution network and by s 20 of that Act_,_ actions against Aurora's distribution business may be commenced against the respondent.
7. At pars 10 to 17 of the amended statement of claim at trial, the appellant pleaded that the scope of the Hydro Electric Commission and Aurora's duty to the appellant in the supply and distribution of electricity to the property required it to install the pole and associated infrastructure in a specified manner and that it did not. At par 18 it was pleaded that each of the matters pleaded in paragraphs 11 to 17 inclusive constituted a negligent breach of duty by the respondent.
8. It is well settled that a person supplying services to another person for reward owes that person a duty of care. It is a sophisticated argument, which I reject, to say that all that the respondent supplied to the appellant was the pole, and that the pole was not "consumed" by the appellant. There was no contract suggested as existing between the parties but the respondent clearly operated its business for reward. The supply of electricity may have remained with Aurora but the respondent's acquisition of the rights and liabilities of Aurora was admitted insofar as the installation and maintenance of the distribution network was concerned. The respondent was a provider of infrastructure along which a supplier of electricity delivered electricity to consumers and as such had, in my opinion, a duty of care of a common or garden variety. In any event, in Munnings v Hydro Electric Commission [1971] HCA 27; (1971) 125 CLR 1, Barwick CJ was among the members of the High Court who inclined to the view that his Honour expressed as follows at p11:

"It was the want of maintenance in the operation of carrying electricity in the conductors by means of the pole which caused the harm to the plaintiff. Thus, Thompson v. Bankstown Corporation [1953] HCA 5; (1953) 87 CLR 619 is an authority for the proposition that a person bringing such a substance as electricity into proximity of the public owes a duty to take care by the adoption of reasonable steps or methods that it does not harm those whom it ought to forsee might otherwise come into contact with it."

1. At the very commencement of his opening address, senior counsel for the appellant said, speaking to his written opening submissions, provided to his Honour and to senior counsel for the respondent, Mr McTaggart SC:

"Now, your Honour if we go to the introduction on the second page of the document. And I do intend to read this document, your Honour, but it's - rather than having your Honour go away and read it's useful because there are documents interpolated into it that we need to go to. So, the cause of action in this matter arises at common law in negligence but is governed by various parts of the Civil Liability Act, 2002. So what the Civil Liability Act does is, it doesn't create a cause of action but it governs it in many ways in relation to breach. So, strictly we still have a common law action rather than a statutory one but it's very much statutory these days.

There may be some dispute as to the duty of the defendant, the scope of that duty in (sic) breach, but at its heart this is a case about causation of the harm suffered by the plaintiff. It is a circumstantial case; that is there's no direct evidence as to what - cause (sic) the harm at issue. The plaintiff invites the court to use a process of inferential reasoning from circumstantial evidence. Now, your Honour, just what that means is really at the heart of our case. What that means as a matter of law is at the heart of our case. I therefore wanted to take your Honour if I might to the case of Langmaid v Dobsons Vegetable Machinery Pty Ltd 6 [2014] TASFC." [Emphasis added.]

1. In his opening address, senior counsel for the respondent said:

"The only duty that's pleaded, your Honour, is statutory duty, that is, a duty arising under the Industry Act and in accordance with the Code for which that Act provides. That's what s 8 of the statement of claim pleads and it then goes on to define the scope of that duty as being in accordance with that code, good industry practice. There is no plea of any Commonwealth (sic) duty, and the opening today, it's the first time in approximately five years of litigation that such a duty has been alleged, notwithstanding there's been three amendments to the statement of claim, including one which was ordered yesterday. So the defendant holds the plaintiff to its pleadings and, your Honour, we will be addressing our defence to the statutory breach which is pleaded."

1. At the conclusion of the respondent's opening address there occurred the following exchange between senior counsel for the appellant and the learned trial judge:

"MR READ SC: Your Honour there's one matter that arises that I must - I must mention and that is that my learned friend asserts that we have only an action for breach of statutory duty.

Your Honour I'm - I must say I'm completely taken by surprise by that. I've always understood this to be a common law action as well a breach of statutory duty and the pleading arises in paragraph 18 of the statement of claim.

Now I don't want my learned friend to be taken by surprise by this. If some amendment needs to be made so that it is even more clear then - then that ought to occur but -

HIS HONOUR: Well that's a matter for you to reflect upon I suppose in light of his submission is it not.

MR READ SC: Um well it is I suppose your Honour but para 18 makes it very clear that this is a negligent breach of duty.

MR READ SC: By reason of matters in 10 to 17 which don't include the statutory duty. I mean I'll contemplate your Honour but that's um -

HIS HONOUR: Look I think that's the way to go and Mr McTaggart has flagged the way in which the defendant sees the case that's put against it and how it intends to respond to that case and ultimately it'll be a matter for submission based upon the evidence. I don't think it's a case where you need to be concerned that Mr McTaggart is in some way likely to be taken by surprise.

HIS HONOUR: I think he's simply putting a point of view about the way the issues are raised in the pleadings and how the defendant considers it necessary to - to respond and that's entirely a matter for it -

HIS HONOUR: For its judgement, if it misses the mark it misses the mark. If it doesn't well it doesn't.

1. Thereafter, the trial continued over some eleven days and no further word was uttered to suggest that the respondent was not meeting a cause of action in negligence or that the suggested amendment was required. Indeed, in her contribution to the respondent's closing submissions, junior counsel, Ms Cuthbertson, said, before the pleading point was taken by her leader:

"So now really the only issue that remains alive is - to be determined is whether in the event of negligence being proved, what is the extent of the loss of profit flowing from that negligence, and in my submission, notions of double recovery are of no application in this case ...". [Emphasis added.]

1. It certainly seems to me as though the parties, after the exchanges in opening addresses, conducted the case as involving a cause of action in negligence up until the point in his closing address when senior counsel for the respondent took the pleading point.
2. Be that as it may however, a plaintiff needs only to plead material facts capable of establishing a cause of action in negligence. It is not necessary to name or identify the specific cause of action upon which the appellant relies, see Roberts v Roberts [1957] Tas SR 84 at 99, per Crisp J, with whom Burbury CJ and Green J agreed, citing Esso Petroleum Co Ltd v Southport Corporation [1956] AC 21 at 238 and Halsbury's Laws of England, 2nd ed, Vol 25, at 239.
3. In Jones v Clyde Welshpool Pty Ltd [2000] TASSC 130, 9 Tas R 391 at [9], Blow J (as he then was) confirmed that a statement of claim will plead a cause of action in negligence where material facts giving rise to the duty are pleaded, and concluded that a plaintiff was not bound to state the legal effect of the facts relied upon, which is a question of law that need not be pleaded. See also Munnings v HEC (above) at 6 per Barwick CJ, where his Honour noted the "melancholy fact" that pleading as a means of determining the issue of fact to be tried, "seems to have failed, largely because as an art it has ceased to be practised".
4. This position remains unaltered by the Civil Liability Act 2002, as s 3A(5) provides that the Act is not a codification of the law relating to civil claims for damages for harm.
5. In my view, ground 1 of the notice of appeal should succeed as at the very least, the amended statement of claim at trial pleaded material facts capable of establishing a cause of action in negligence. That is so, in my view, even were it necessary to plead facts going to the foreseeability of the relevant risk, or reliance, or vulnerability. The pleading was pregnant with the salient innuendoes.
6. As can be seen, I do not regard this case as involving a novel category of duty, but to the extent to which it might have been necessary to establish relevant indicators of duty in the proceedings below, either because a novel category of duty was indeed involved, or the claim was one for pure economic loss, or because it was required by the principle to be derived from Sutherland Shire Council v Heyman [1985] HCA 41; (1985) 157 CLR 424, those indicators are, to my mind, self-evident from the pleadings and the uncontested evidence of the relationship between the parties.

"The learned trial judge erred in failing to consider and decide the circumstantial case put by the Plaintiff as he did not consider the weight to be given to the united force of all the circumstances put together."

1. The words of Kiefel CJ in Lee v Lee [2019] HCA 28, 93 ALJR 993 at [3] are apposite to the present case. Her Honour said:

"Each of the parties sought to prove the factual scenario for which they contended by expert evidence of different kinds, from which inferences could be drawn. When considering the Court of Appeal's reasons, it is useful to bear in mind what fact a party has undertaken to prove, and to identify the evidence by which it seeks to prove it and the evidence by which the other party seeks to meet and deal with that case." [Emphasis added.]

1. The starting point in this appeal, to my mind, is to recall that which the appellant set out to prove by way of a circumstantial case and to note the applicable legal principles with respect to the discharge of the appellant's onus of proof at trial. The second and distinct step is to consider the extent to which the evidence adduced on behalf of the respondent might be said to have met and dealt with the appellant's case.
2. The existence of a risk of harm arising from the operation and maintenance of infrastructure along which a provider of electricity delivers it to consumers need hardly be canvassed. Leaving aside for the moment the question of the scope of the respondent's liability, the appellant at trial was required to establish that negligence caused the particular harm, which involved proving that the alleged negligence was a necessary condition of the occurrence of the harm. That is to say proof of a causal connection between the respondent's alleged breach of duty and the appellant's damage, on the balance of probabilities. Unlike a criminal case based on circumstantial evidence, the appellant did not have to exclude every hypothesis consistent with an absence of negligence on the part of the respondent.
3. In practical terms, the question of factual causation for the learned trial judge was whether, left uncontradicted, the appellant's evidence established one or more of its three hypotheses on the balance of probabilities. If so, the examination would then turn to whether the respondent, by its evidence, (or argument), had established that none of the appellant's hypotheses rose above speculation (Progressive Recycling Pty Ltd v Eversham [2003] NSWCA 268, 40 MVR 141 at [7] per Young CJ in Eq (Ipp JA and Davies AJA agreeing); Condos v Clycut Pty Ltd [2009] NSWCA 200 per McColl JA at [68] (Campbell and Macfarlan JJA agreeing), or had established that the appellant had failed to prove facts sufficient to support some positive inference "which arises as an affirmative conclusion from the circumstances proved in evidence ... to the reasonable satisfaction of a judicial mind" (Jones v Dunkel [1959] HCA 8; (1959) 101 CLR 298 per Dixon CJ at 304).
4. In undertaking such an examination of the evidence, it is as well to bear in mind what was said by Porter J, with whom Pearce J agreed, in Langmaid v Dobsons Vegetable Machinery Pty Ltd [2014] TASFC 6 (Langmaid), at [125], namely:

"[125] As to the ultimate question of proof on the balance of probabilities by inference, in Lithgow City Council v Jackson (2011) 244 CLR 352 at 386 [94], Crennan J noted that whilst a more probable inference may fall short of certainty, it must be more than an inference of equal degree of probability with other inferences so as to avoid guess or conjecture. Her Honour continued:

'In establishing an inference of a greater degree of likelihood, it is only necessary to demonstrate that a competing inference is less likely, not that it is inherently improbable'." [Emphasis added.]

1. It should also be borne in mind that the competing inference advanced by the respondent at trial was merely that, contrary to the appellant's evidence, the respondent's equipment did not malfunction in a way that caused the PLC to fail, and that some unexplained but postulated event within the appellant's own internal power system caused the damage. As I apprehend it, no particular alternative cause of that failure was presented in any reasoned way. In a circumstantial case, that of itself may be of significance to the ultimate question of proof, particularly when, as Porter J pointed out in Langmaid at [123]:

"[123] Expert opinion of a possibility can be used as circumstantial evidence, and a finding of factual causation may be made where the expert evidence 'does not rise above the opinion that a causal connection is possible'; the evidence will be sufficient if, but only if, the materials justify an inference of probable connection: Fernandez v Tubemakers of Australia Ltd [1975] 2 NSWLR 190 per Glass JA at 197. See also Seltsam Pty Ltd v McGuiness (2000) 49 NSWLR 262 per Spigelman CJ at 274 - 275 [79]-[83] ..." [Emphasis added.]

1. As to the correct approach to the evidence in a circumstantial case the High Court recently, in Fennell v The Queen [2019] HCA 37, 93 ALJR 1219 at [82] reaffirmed the propositions espoused by Gummow, Hayne and Crennan JJ in R v Hillier [2007] HCA 13, 228 CLR 618 at 638 [48], namely:

"48 Often enough, in a circumstantial case, there will be evidence of matters which, looked at in isolation from other evidence, would yield an inference compatible with the innocence of the accused. But neither at trial, nor on appeal, is a circumstantial case to be considered piecemeal. As Gibbs CJ and Mason J said in Chamberlain [No 2][1]:

'At the end of the trial the jury must consider all the evidence, and in doing so they may find that one piece of evidence resolves their doubts as to another. For example, the jury, considering the evidence of one witness by itself, may doubt whether it is truthful, but other evidence may provide corroboration, and when the jury considers the evidence as a whole they may decide that the witness should be believed. Again, the quality of evidence of identification may be poor, but other evidence may support its correctness; in such a case the jury should not be told to look at the evidence of each witness "separately in, so to speak, a hermetically sealed compartment"; they should consider the accumulation of the evidence: cf Weeder v The Queen[2].

Similarly, in a case depending on circumstantial evidence, the jury should not reject one circumstance because, considered alone, no inference of guilt can be drawn from it. It is well established that the jury must consider "the weight which is to be given to the united force of all the circumstances put together": per Lord Cairns, in Belhaven and Stenton Peerage[3], cited in Reg v Van Beelen[4]; and see Thomas v The Queen[5] and cases there cited.'

'All the circumstances of the case must be weighed in judging whether there is evidence upon which a jury may reasonably be satisfied beyond reasonable doubt of the commission of the crime charged. There may be many cases where it is extremely dangerous to rely heavily on the existence of a motive, where an unexplained death or disappearance of a person is not otherwise proved to be attributable to the accused; but all such considerations must be dealt with on the facts of the particular case. I cannot think, however, that in a case where the prosecution is based on circumstantial evidence any part of the circumstances can be put on one side as relating to motive only and therefore not to be weighed as part of the proofs of what was done.' (emphasis added)"

1. Factual causation in this case of course involves consideration of s 13(1) of the Civil Liability Act. The "but for" test is the relevant inquiry: Adeels Palace Pty Ltd v Mourbarak [2009] HCA 48, 239 CLR 420 at [42]- [45]; Strong v Woolworths [2012] HCA 5, 246 CLR 182 at [18].
2. Notwithstanding a somewhat ambiguous statement by the learned trial judge at [157] of his reasons, as to the role of s 14 of the Civil Liability Act, that section is concerned with the onus of proof of factual causation, that is to say, causation as a fact. The words of the section "[i]n deciding liability for breach of a duty, the plaintiff always bears the onus of proving, on the balance of probabilities, any fact on which the plaintiff wishes to rely relevant to the issue of causation", cannot sensibly be construed as requiring that every intermediate fact asserted as a strand in the cable of a circumstantial case going to causation must itself be proved on the balance of probabilities. Nonetheless, the respondent embraces such a construction in its submissions on this appeal, relying on Chamberlain v The Queen (No 2) [1984] HCA 7; [1984] 153 CLR 521 at 536. Chamberlain is no longer authority for the proposition advanced by the respondent.
3. As was pointed out in Neill-Fraser v Tasmania [2012] TASCCA 2 at [156]- [160] by Crawford CJ, with whom the other members of the Court of Criminal Appeal agreed:

"156 It was submitted for the appellant that the direction was erroneous and that the judge should have directed the jury that they could not return a verdict of guilty unless they were satisfied beyond reasonable doubt of the facts essential to their reasoning towards proof beyond reasonable doubt of each element of the crime.

157 Although arguments of that kind would have been expected following Chamberlain v R (No 2) [1984] HCA 7; (1984) 153 CLR 521, their validity was put to rest, for the circumstances of this case, by Shepherd v R [1990] HCA 56; (1990) 170 CLR 573. A direction that an intermediate circumstantial fact must be proved beyond reasonable doubt before it may be used as a basis for inferring guilt, is not usually required.

158 What is often quoted as a classic statement on the position is that of Lord Cairns in Re Belhaven and Stenton Peerage (1875) 1 App Cas 278 at 279:

'... in dealing with circumstantial evidence, we have to consider the weight which is to be given to the united force of all the circumstances put together. You may have a ray of light so feeble that by itself it will do little to elucidate a dark corner. But on the other hand, you may have a number of rays, each of them insufficient, but all converging and brought to bear upon the same point, and, when united, producing a body of illumination which will clear away the darkness which you are endeavouring to dispel.'

159 In Shepherd v R, Dawson J, at 579, explained the position concerning whether an intermediate fact must be proved beyond reasonable doubt. His Honour said:

'On the other hand, it may sometimes be necessary or desirable to identify those intermediate facts which constitute indispensable links in a chain of reasoning towards an inference of guilt. Not every possible intermediate conclusion of fact will be of that character. If it is appropriate to identify an intermediate fact as indispensable it may well be appropriate to tell the jury that that fact must be found beyond reasonable doubt before the ultimate inference can be drawn. But where - to use the metaphor referred to by Wigmore on Evidence, vol 9 (Chadbourn rev 1981), par 2497, pp.412-414 - the evidence consists of strands in a cable rather than links in a chain, it will not be appropriate to give such a warning. It should not be given in any event where it would be unnecessary or confusing to do so. It will generally be sufficient to tell the jury that the guilt of the accused must be established beyond reasonable doubt and, where it is helpful to do so, to tell them that they must entertain such a doubt where any other inference consistent with innocence is reasonably open on the evidence.'

160 Where, therefore, the evidence consists of a number of strands in a cable from which guilt is sought to be inferred, no fact or facts being by themselves necessary for the ultimate inference of guilt, the jury should not be instructed that they must be satisfied that each such fact must be proved beyond reasonable doubt. Instead they may consider the accumulation of the evidence and draw an inference of guilt from a combination of a number of facts, none of which alone would justify a finding of guilt. The matter was explained in Shepherd v R by Dawson J at 579 - 580:

'As I have said, the prosecution bears the burden of proving all the elements of the crime beyond reasonable doubt. That means that the essential ingredients of each element must be so proved. It does not mean that every fact - every piece of evidence - relied upon to prove an element by inference must itself be proved beyond reasonable doubt. Intent, for example, is, save for statutory exceptions, an element of every crime. It is something which, apart from admissions, must be proved by inference. But the jury may quite properly draw the necessary inference having regard to the whole of the evidence, whether or not each individual piece of evidence relied upon is proved beyond reasonable doubt, provided they reach their conclusion upon the criminal standard of proof. Indeed, the probative force of a mass of evidence may be cumulative, making it pointless to consider the degree of probability of each item of evidence separately'."

1. Porter J in his judgment in Neill-Fraser, further explored the notion of indispensable links in a chain of reasoning towards an inference of guilt and the place for a "prudential direction". He said at [226]-[228]:

"226 By ground 6 the appellant complains that the trial judge was wrong in directing the jury that the facts and circumstances from which a conclusion of guilt may be drawn need only be established to the satisfaction of the jury. The appellant argued that the trial judge should have directed the jury that they could not return a verdict of guilty unless they were satisfied beyond reasonable doubt of the facts essential to their reasoning towards proof beyond reasonable doubt of each element of the crime. Ground 7 makes that complaint specifically referrable to the issue of motive.

227 As Crawford CJ has held, the primary answer to the appellant's submissions is to be found in Shepherd v R [1990] HCA 56; (1990) 170 CLR 573, and the well-known statements of Dawson J at 579 - 580, the particularly relevant parts of which have been set out in the learned Chief Justice's reasons at [159] - [160]. It is not the law that in all cases a trial judge should instruct the jury that they must be satisfied beyond reasonable doubt of all facts essential to their reasoning leading to satisfaction of guilt. However, it may sometimes be necessary or appropriate to identify an "intermediate fact" and to tell the jury that they must be satisfied beyond reasonable doubt of such fact before the ultimate inference of guilt can be drawn: Shepherd per Dawson J at 579, R v Merritt [1999] NSWCCA 29 at [70] - [71].

228 In Shepherd, Dawson J said that such a warning would not be appropriate where the evidence consisted of strands in a cable rather than links in a chain, the metaphor of Wigmore's which Callaway JA has described as helpfully describing 'two distinct kinds of reasoning': R v Kotzmann [1999] VSCA 27; [1999] 2 VR 123 at 129 [16]. As Callaway JA went on to point out at [17], it does not follow that 'wherever sequential reasoning is necessary or appropriate, each link in the chain must be established beyond reasonable doubt'. [Original emphasis] Much depends on the fact or issue in question. As his Honour explained: "One or more of the individual facts may be established only by sequential reasoning but that chain itself be simply one of the strands in the ultimate cable."

"231 At least in Victoria, there is an abundance of authority for the express proposition that a judge may choose to direct, as a matter of prudence, that a particular fact or matter in a circumstantial case should not be used unless the jury is satisfied beyond reasonable doubt of that fact or matter. A judge is not required to form the view that the evidence is an indispensable link in a chain of reasoning before giving such a direction. Consciousness of guilt evidence is often the subject of a 'prudential direction': see for example the discussion in R v Ciantar [2006] VSCA 263; (2006) 16 VR 26.

232 In R v Kotzmann (above) it was held that the standard of proof of 'additional facts' in a circumstantial case was as explained in Shepherd, and that it did not follow from later High Court cases that there were some additional facts that had to be proved beyond reasonable doubt even though they were not, in the strictly logical sense, indispensable links in a chain of sequential reasoning. Callaway JA referred to the need to direct a jury that it must be satisfied beyond reasonable doubt of a lie, if the lie said to constitute the admission is the only evidence against the accused or is an indispensable link in a chain of evidence necessary to prove guilt, and at 130 [21] said:

'Similarly, it is customary to direct a jury, for prudential reasons, that they should not act on a confession unless they are satisfied beyond reasonable doubt that it was made and that it was true ... The confession may simply be part of the evidence. It may be the proverbial straw that breaks the camel's back'." [My emphasis.]

1. In the present case I can identify no indispensable link in a chain of sequential reasoning. To my mind the case is purely a "strands in a cable" case, albeit some individual strands may rely on sequential reasoning.
2. The respondent's written submissions are permeated with the contention that no error has been identified by the appellant as to the trial judge's findings because:

"As identified by His Honour at [157], Brocklands bore the onus of proving each fact on which it relied, relevant to the issue of causation, on the balance of probabilities. Proving that something 'could' have occurred does not meet that onus."

1. If that is what the learned trial judge meant at [157] and I do not believe it was, then as a statement of law it is incorrect. That such a finding has not been the subject of a specific ground of appeal is of no consequence as this Court, in reviewing the whole of the evidence, is required to approach the circumstantial evidence in accordance with the law.
2. Turning to the role of this Court on this appeal, as the plurality noted in Lee v Lee (above), at [55]:

"[55] A court of appeal is bound to conduct a 'real review' of the evidence given at first instance and of the judge's reasons for judgment to determine whether the trial judge has erred in fact or law. Appellate restraint with respect to interference with a trial judge's findings unless they are 'glaringly improbable' or 'contrary to compelling inferences' is as to factual findings which are likely to have been affected by impressions about the credibility and reliability of witnesses formed by the trial judge as a result of seeing and hearing them give their evidence ..." [Emphasis added.] [Footnotes omitted.]

1. Appellate restraint extends to findings of secondary facts which are based on a combination of those impressions and other inferences from primary facts: Lee v Lee (above), at [55].\
2. It is true, as the respondent submits, that the parties called multiple expert witnesses with competing theories on causation, five of whom gave evidence concurrently and engaged in debate in relation to their own evidence, and the evidence of others. For my part however, on reading the transcript of that concurrent evidence, it is easier, as to reliability and weight, to experience the benefit the learned trial judge had, of hearing that evidence and observing the witnesses, than it would have been if the expert evidence had been taken conventionally.
3. In the present case, the learned trial judge did not base any of his findings on the credibility of the witnesses who gave evidence, and, with respect to the expert witnesses in particular, his Honour said at [207]:

"[207] The Court does not doubt the honesty, or independence of any of the experts. The court's observation of the experts is not material to its conclusion, nor is credit a matter relevant to the conclusion."

1. Next, while this Court has an obligation to conduct a "real review" of the evidence given at first instance and of the learned trial judge's reasons for judgment, to determine whether his Honour has erred in fact or law, that review must to an extent be confined to that required by the grounds of appeal and the submissions of the parties. The appellant asserts that the trial judge erred by failing to consider the weight to be given to the totality of the circumstantial evidence but, leaving aside the asserted "error as to evidence", that his Honour erred in preferring the evidence of the respondent's experts over that of the appellant's experts, "without analysis of the reasoning underpinning the opinions of the expert witnesses", and the asserted failure of his Honour to consider the appellant's "maintenance failure" case, there are only specific errors alleged and they circumscribe the extent of the required review. It is noted of course that the respondent alleges that his Honour erred in finding that the appellant's claim was not one for pure economic loss.
2. Finally, as to the approach to the question of the legal consequences of any breach by the respondent of a duty of care owed to the appellant, it is useful to remember, as Porter J pointed out in Langmaid at [49]:

"In terms of the general principle, I agree with Blow CJ that there is nothing impermissible in a trial judge first making findings of fact about whether there is a causal connection between conduct around which breaches of duty are alleged and damage, and going on to consider the legal consequences of those findings to the extent necessary: Amaca Pty Ltd v Booth [2011] HCA 53; (2011) 246 CLR 36 per Gummow, Hayne and Crennan JJ at 60 [64]. That is particularly so where there is no real argument about the existence of the pleaded duties and about breaches of those duties."

1. Erred at [178] in failing to find that on 10 December 2010, the earthing system resistance was greater than 30 Ohms.
2. Erred at [191] in failing to find that the separation between the high voltage and low voltage earthing conductors/electrodes was less than 2 metres.
3. Erred at [201] in finding that the evidence of a flashover event was 'mere conjecture'.
4. Erred at [39] in finding that the cost of rectifying 50,000 transformers would be 'onerous to the point of being unreasonable' in circumstances where there was not any evidence before the Court of that costs of rectification or that it was even needed.
5. Erred at [178] in finding that excavations may have altered the earthing resistance around the Pole.
6. Erred in finding at [259] that there was not a high voltage surge event that damaged the PLC.
7. Erred in failing to find that the agreed distance of separation of the high and low voltage conductors could give rise to a flashover event.

1. Erred at [124] in disregarding the evidence of Mr Richardson.
2. Erred at [131] in attributing the evidence of Mr Whiddon no weight.
3. Erred in admitting the evidence of Mr Jarman insofar as it consisted of expert evidence and in the alternative erred in considering his evidence to have the weight of evidence of an expert.
4. At [155] the learned trial judge erred in concluding that the evidence of Mss Brock, Hetherington and Mr Phillips was inadmissible opinion pursuant to s 76 of the Evidence Act 2001.
5. Erred at [194] in according Mr Reeves' evidence the status of expert evidence.
6. Erred in respect of the evidence of Dr Muthumuni:

(b) In considering it on the basis that that it was tendered by consent [210] when it was not [T525 - 553], and;

(c) At [248] in disregarding the absence of a proper basis for his opinion because the plaintiff did not put the shortcomings listed at [243 and 244] to Dr Muthumuni.

1. Erred in preferring the evidence of the Defendant's experts over that of the Plaintiff's experts without analysis of the reasoning underpinning the opinions of the expert witnesses."
2. As noted, these asserted errors delineate to an extent at least, the matters which this Court must examine before ultimately turning to consider whether the combined weight of the appellant's evidence was sufficient to establish the inference that the respondent's negligence was causative of the appellant's harm. It is acknowledged however, that the errors alleged in pars 8 and 16 above require not just an examination of whether the learned trial judge analysed the reasoning underpinning the opinions of the expert witnesses, but also an examination of the question of which experts he ought to have preferred in the light of the totality of the evidence. That is, assuming that it is necessary for the appellant to have recourse to expert evidence at all, in order to make out a circumstantial case as to factual causation.

1. As can be seen from what I have already said, I do not doubt that this ground of appeal, by raising the question of whether the learned trial judge considered the combined weight of the appellant's evidence, requires this Court to conduct a review of the evidence given below, and of the learned trial judge's reasons for judgment, in order to determine whether he has erred in fact or law. It is not however accurate or helpful to articulate this ground in the way the appellant has done by taking up the words of Lord Cairns in Bellhaven v Stenton Peerage [1875] 1 AC 278 at 279.
2. It is not just the weight to be given "to the united force of all the circumstances put together", as his Lordship put it, that must be considered. Rather it is whether on an examination of the whole of the evidence capable of giving rise to an inference, it is more probable than not that the appellant's damage was caused in one or more (or, conceivably perhaps, all) of the three ways in which the appellant says that it was caused damage.
3. In broad terms, the appellant proposed two potential causal mechanisms, namely, a flashover from the HV to LV line, and/or electricity entering the neutral conductor by reason of a defective earthing system. There was no direct evidence to prove either or both of these mechanisms so the case was necessarily circumstantial.
4. At trial the first mechanism was bifurcated, so the appellant advanced, what I apprehend to be three distinct hypotheses.
5. The first hypothesis was that because of the distance between the high voltage (HV) bushing and the low voltage (LV) conductor, resulting from the proximate placement of the transformer and the location of the LV conductor, a surge of electricity "flashed over" between the two, forcing the surge into the LV system and thus into the PLC on the potting machine, causing damage.
6. The second hypothesis was predicated on a mechanism intended to provide protection from a surge, known as the arc gap rods. To work as intended, the appellant contended that these should be correctly aligned (and that they should not be painted). It contended that the arc gaps ought to have been set to 50mm in series (that is two gaps of 25mm). It was an agreed fact that the right hand spark gap was 60mm in series and it was said that it is clear from the video (Exhibit D54) that the left hand gap was 65mm in series, thus compromising their effectiveness. The appellant argued that the result of these irregularities was to render the mechanism such that a high voltage surge could find its way to the low voltage "pathway" and thus to the PLC, causing damage.
7. The third hypothesis was that the HV and LV earths running down the pole and into the ground, were not two metres apart on the relevant date. Insufficient separation makes it possible for electricity from a power surge to travel through the ground from the high voltage earth to the low voltage earth and thence into the low voltage power supply and into the PLC.

1. The first evidence canvassed by the learned trial judge was that of Karen Brock and Tim Phillips. His Honour summarised their evidence and that of Sandra Hetherington, at [112]-[119] as follows:

"[112] Karen Brock, a director of the plaintiff, gave evidence. She moved to Markfield in 1998 with her partner and fellow director Tim Phillips.

[113] In the period beginning February 1998, Ms Brock said there were problems with the electricity which resulted in appliance failures. She said the power would 'just keep going off and then back on again'. Sometimes this would happen twice a day, sometimes five times in a day, sometimes once a week. She described it as 'spasmodic'.

[114] She said that household equipment such as bread makers and microwaves routinely failed, and she was replacing three or four bread makers and two microwaves a year. A TV which was received as a wedding present in 2008, suffered a damaged circuit board and was replaced under warranty. She described many other problems including with a UV water sterilizer with a light globe which regularly malfunctioned, and in the small greenhouses there were electrical problems in the period 2003 to 2006. She repaired a number of items of electrical equipment herself, including computers. She told the Court that she kept old computers for spare parts, and would 'rob the old computers' for ''power supplies, and circuit boards.'

[115] In 2001 she said that a glasshouse caught fire and a lot of propagation material within it was damaged. Upon returning from a school function, flames were observed in the nursery. She believed that a heat mat had caught fire and had spread to the whole greenhouse.

[116] Ms Brock claimed electrical problems occurred at Markfield until 2012.

[117] Asked whether there was any coincidence between the discovery of damage to equipment, and the outages that she described, she said she had not made notes at the time and was unable to say. I nevertheless consider that the Court is being invited to draw a connection between these events, or at least some of them, and the interruptions to the power supply, she describes.

[118] The evidence of electrical problems is confirmed by her partner, Tim Phillips. He kept a calendar of power outages, and other interruptions to the electricity supply. (It was called the 'cow calendar' because the information is recorded on a calendar with images of cows on it.) It was an attempt to keep track of electrical interruptions, and problems experienced. He described a number of these, including pumps malfunctioning, and an electric fence requiring repair.

[119] A previous occupier of the property, Sandra Hetherington, gave evidence. She had worked at Markfield for a former owner and gave evidence of similar types of electrical problems."

1. This evidence relates of course to all three of the appellant's hypotheses. The learned trial judge dealt with the probative effect of an aspect of the evidence at [150]-[155] as follows:

"[150] The Court will consider the plaintiff's case, beginning with the evidence of electrical failure at Markfield. The episodes of electrical interruption and appliance failure are relied upon by the plaintiff to expose a history of problems said to be indicative of the defendant's failure to meet its statutory obligations. The Court has not set out every episode recounted in evidence, but it accepts the plaintiff's evidence that there were numerous such instances in the period ending 2012. It accepts that Ms Brock undertook a number of repairs to computers in consequence of their malfunctioning, and that numerous household appliances required repair or replacement.

[151] The plaintiff submits the incidence of such failures was 'unusually high' compared with common knowledge. 'Common knowledge' is an unexplained concept here, but I interpret it as meaning 'common experience', being the experience of users of electricity generally. Whether that is so it is unnecessary to decide. The plaintiff invites a finding that a causal link is established between these episodes of appliance failure and network outages.

[152] It cannot be doubted that in some instances there is such nexus. Indeed, in a letter in 2003, the defendant attributes one such interruption, to the operation of a recloser at Clarence Point. And it acknowledges that an outage at Markfield on 6 October 2009 was caused by vegetation. There are other episodes it acknowledges, for example an outage on 5 February 2010 recorded in the 'cow calendar' said by the plaintiff's directors to coincide with a computer and an electric fence 'energizer' suffering damage. The plaintiff also refers to damage to a cable PI and some scales and transformer on 10 December 2010, the day the PLC is alleged to have suffered harm. Another episode in 2015 referred to by Mr Gillespie for which there is no record, is also referred to.

[153] The power interruptions in 2003 and 2009 explained by the defendant from its own records, disclose an interruption to the power supply when the protective mechanisms within the system operated correctly. There is no evidentiary basis for a finding that these episodes are relevant to the failure of the PLC, and such a conclusion is speculative. Similarly, the submission that the episode in February 2010 is probative of the claim made in the action, is not established. The Court reaches no conclusion about the episode in 2015 because it is not disclosed in any sufficient detail to sustain a finding. It also postdates the event the subject of the claim. Nor does the Court feel able to draw any inference from these episodes, viewed together as a series of outages coinciding with interruptions at Markfield.

[154] In respect of the appliance failures generally, no evidence capable of sustaining a meaningful conclusion probative of matters in issue was led by the plaintiff. For example, there was no evidence of any specialist diagnosis of the damage to the appliances, nor of the repairs required; there are no invoices disclosing the work done, nor any reports from the repairers. There is nothing to show whether a manufacturer's fault was the cause of failure. The LG TV for example was replaced under warranty. That is consistent with the manufacturer accepting fault, a basis for replacement of the TV the plaintiff directors have accepted.

[155] The plaintiff's (sic) submission with respect to the probative value of these matters is based upon inadmissible opinion. Opinion evidence may only be received in accordance with s 76 of the Evidence Act 2001, and as explained in Dasreef v Hawchar [2011] HCA 21, neither director, nor Ms Hetherington, is qualified to express the opinions proffered. Insofar as an expert witness says, the events are not inconsistent with such hypothesis, or that the episodes offer a circumstance from which it is reasonable to draw an inference about the quality of the power supply and the particular damage sustained, the Court declines to draw that inference because the factual basis for such claim is not established. No proper inference can be drawn from anecdotal evidence of electrical failure, or other electrical damage, to sustain the plaintiff's case on this point. I afford this evidence no weight."

1. The appellant asserts in the notice of appeal that the learned trial judge erred at [155] in concluding that the evidence of Ms Brock, Ms Hetherington and Mr Phillips was inadmissible opinion pursuant to s 76 of the Evidence Act 2001. That must be correct, with respect.
2. The appellant's case was a circumstantial case which proceeded on the basis that there had been an unusual history of unexplained damage to electrical items at the property dating back over ten years prior to the contested event, and which ceased in 2012, after the respondent made alterations to the configuration of the equipment on the pole. The evidence of the occasions on which such damage occurred was not led as opinion evidence, rather, as evidence of fact. The relevant facts were the observations made by these three witnesses as to unusual and unexplained occurrences with electrical equipment at the property.
3. This evidence was capable of constituting "strands in a cable", as opposed to "links in a chain", (Wigmore on Evidence, vol 9 (Chadbourn rev 1981), par 2497, pp 412-414), of proof of a causal connection between the equipment on the power pole and the damage to the PLC. Whether it did so or not was a matter for the learned trial judge, now for this Court. But it was not led as evidence of an opinion that the equipment on the pole was responsible for the damage to the PLC and, with respect, it ought not to have been so dismissed by his Honour.

1. The learned trial judge next canvassed the evidence of Mr Eric Richardson. Mr Richardson's evidence was the subject of an agreed fact that in approximately August 2009 he was engaged by the appellant to install a Phase Change Converter PC8 three phase converter (the PC), a three phase switch and three phase cabling in the potting shed and that the phase converter produced three different phase supplies of electricity being 160 volts, 230/240 volts and 360 volts when measured to earth. His Honour dealt with Mr Richardson's evidence at [122]-[124] as follows:

"[122] As recorded in the agreed facts, Mr Richardson is the licenced electrical contractor who installed the PC in the shed, in August 2009. He had not installed one of these devices before, though he did not identify any particular problems in doing so. The function of the PC was to convert the single-phase electricity supply to a three-phase supply, a cheaper alternative than installing three-phase power.

[123] His evidence was that other electrical installations at the potting shed were installed in accordance with the appropriate wiring rules, but did not elaborate upon nor describe those rules.

[124] He worked for the plaintiff later in 2009 making alterations to wiring connections. He raised an invoice for that work but the details of the work he undertook were not disclosed so no one is able to say what changes he made to the wiring, or make any judgment about the significance of that work to the subsequent event. The defendant contends that his evidence lacks sufficient detail with respect to those matters to be forensically meaningful. I agree. The Court is unable to derive any assistance from assertions to the effect that electrical installations, including those relevant to the potting machine, were installed in accordance with wiring rules (or indeed any standard) because the detail is not identified."

1. The appellant asserts in the notice of appeal that the learned trial judge erred in disregarding the evidence of Mr Richardson. That must also be correct, with respect. The agreed fact comprised the evidence of a licensed electrical contractor who asserted that the electrical installations at the potting shed were in accordance with what he understood, as a licensed electrical contractor, to be the "wiring rules". The evidence may not have identified those rules but that does not mean that the evidence was of no value. If left uncontradicted by other evidence at trial, the agreed fact was capable of constituting another "strand in the cable" by eliminating faulty wiring in the PC in the potting shed as a possible cause for the failure of the PLC.

1. The learned trial judge then dealt with the evidence of Mr Paul Whiddon, at [129]-[131], as follows:

"[129] The agent for the potting machine supplier was Mr Paul Whiddon. He was instructed by his employer, Tyco Tamar to attend at the Brocklands Nursery to investigate the failure of the potting machine. His evidence is the only evidence about the condition of the PLC after the potting machine ceased to operate in December 2010.

[130] When he arrived the machine was plugged in and switched off. The PLC was a basic unit known as a 'shoe box', its code written in ladder format, and upon his inspection 'in situ' it appeared to be correctly wired and installed. He told the Court that the electrical connections to the PLC measured between 230 and 240 volts, which is the correct voltage.

[131] His observations of the PLC are described as being consistent with shorting of some of the tracks around the communication tracks on the printed circuit board. The relevance of such observation to the issue of causation is an untested claim. The defendant's evidence, through its expert Anthony Gillespie is the photo, the only evidence of the PLC which exists, does not assist in arriving at an opinion about what caused its failure. In the context of the whole of the evidence as to causation, the court does not rely on the untested evidence that the condition of the PLC is consistent with the claimed cause of damage."

1. In the notice of appeal the appellant asserts that his Honour erred in attributing the evidence of Mr Whiddon no weight. Once again, that must, with respect, be correct. The evidence taken by itself may not have been evidence sufficient to prove that the condition of the PLC was consistent with the claimed cause of damage, but the evidence that the PLC was correctly wired and installed and the evidence that the communication tracks showed what Mr Whiddon believed was "shorting" on the printed circuit board, was evidence capable of constituting further "strands in the cable" of proof.
2. It must also be pointed out in this regard that the appellant's expert witnesses, Messrs Piper, Page and Johnston gave evidence based on the photograph referred to by his Honour (part of Exhibit P2), opining that the marks Mr Whiddon observed were consistent with a voltage surge as opposed to an under voltage event, as was suggested by the respondent's expert Dr D'Alessandro. Neither Dr D'Alessandro's evidence nor that of Mr Gillespie, who was unable to offer an opinion on that issue, detracts from the potential weight of Mr Whiddon's observation.
3. Mr Whiddon's evidence, if left uncontradicted by other evidence, was in my view capable of supporting an inference of a voltage overload and of tending to disprove the possibility of computer malfunction or an internally, electrically caused failure of the PLC circuit board. His Honour, with respect, ought not to have abandoned any reliance upon the evidence. Lack of evidence about the precise mechanism of how damage came to be suffered does not necessarily prevent an inference being drawn about a causal link between facts proved and the harm: Langmaid (above), per Porter J at [140].
4. The learned trial judge disposed of the appellant's first hypothesis as to a flashover event, at [193]-[201] in the following way:

"[193] The other mechanism for the surge entering the low voltage system relies upon a flashover event, possible on the plaintiff's case because of the way the installation on the pole was configured.

[194] Robert Reeves was called by the defendant to give evidence relating to the aftermath of flashover events, in particular the presence of visual evidence for such occurrence. The Court accepts his specialist knowledge of such matters, and his ability to express an opinion about this. He told the Court that in his experience as a linesman he had been required to attend in the aftermath of such events. These involved contact between high voltage and low voltage conductors. He said in such cases he observed melting, and marks from burning.

[195] Matthew Jarman, another linesman, was called. He has considerable field experience. His role over a period of about 15 years has been to assess conductors in order to decide if they need replacement. This involves a visual inspection from the ground for signs of damage. Mr Jarman was familiar with a document called the 'Aurora distribution switchgear' operating manual and the 'Aurora power system' safety document. The Court accepted his expertise for the purposes of giving evidence about whether a conductor requires replacement, based upon visual assessment of damage, as distinct from replacement due to ageing. He agreed that a burnout would typically occur when a flashover was caused by a high voltage and a low voltage conductor coming into contact.

[196] He observed no evidence in 2017 whether on the transformer, or anywhere else on the pole, of that having occurred. He agreed that evidence of a flashover is typically observed shortly after the event, principally because repair work is undertaken soon after such event. He agreed that years later such evidence might not be apparent, and that it doesn't follow that such event did not occur. The plaintiff's experts' evidence is consistent with such factual possibility despite the lack of visual evidence.

[197] Mr Gillespie opined that such an event can have explosive consequences, suggesting evidence might be observed long afterwards in some cases. His evidence does not extinguish the possibility of such event here, but it renders it unlikely.

[198] It was suggested by the defendant's expert, Mr Gillespie, that there should be damage to the transformer. Mr Gillespie's opinion was that a surge would cause damage to the internal windings of the transformer, and it was his opinion that since the transformer had not been replaced, such damage had not occurred.

[199] The plaintiffs' expert Mr Piper disagrees submitting that there is insufficient evidence to determine this issue. It is the plaintiff's experts' opinion that damage is related to the magnitude and duration of the surge, and it is thus conceivable that the surge could pass through the LV windings without damage.

[200] The plaintiff submits, there is a 'middle' position too, which means there has been some damage but not sufficient damage to cause the transformer to fail.

[201] The state of the evidence is that there is no visible evidence of a flashover event. That might be explained by the passing of time. It might also suggest there was not such an event. As to the question of whether there should be evidence of damage to the internal windings of the transformer, it cannot be resolved. The evidence led by the plaintiff goes no further than to establish that it is possible. The court finds that the existence of these facts is not proved; it is mere conjecture. It is not sufficient to establish the matters relied upon, on the balance of probabilities." [Emphasis added.]

1. The notice of appeal makes a number of assertions as to the learned trial judge's reasoning and findings on this issue, over and above the general contention that his Honour erred in preferring the evidence of the respondent's experts over that of the appellant's experts without analysis of the reasoning underpinning the respective opinions, and over and above the contention that he erred in finding that there was not a high voltage surge event which damaged the PLC.
2. First the appellant says, his Honour erred at [194] in according Mr Reeves' evidence the status of expert evidence. Second, it is said that he erred in admitting the evidence of Mr Jarman insofar as it consisted of expert evidence, and in the alternative erred in considering his evidence to have the weight of the evidence of an expert. And third, it is said that he erred at [201] in finding that the evidence of a flashover event was "mere conjecture".
3. In my view, it was open to his Honour to treat Mr Reeves and Mr Jarman as ad hoc experts pursuant to s 79 of the Evidence Act. They were both linesmen who had experience in the field of observing the aftermath of flashover events and thus could be properly said to have specialised knowledge based on experience. In Nguyen v The Queen [2017] NSWCCA 4 Schmidt J said at [103]-[105]:

"[103] The concept of an ad hoc expert, who can be called to give opinion evidence such as that sought to be called from the Senior Constable, has long been recognised (see R v Butera [1987] HCA 58; (1987) 164 CLR 180). In Regina v Leung and Wong (1999) 47 NSWLR 405; [1999] NSWCCA 287 it was held at [40] that s 79 is sufficiently wide to accommodate the idea of such an ad hoc expert.

[104] RA Hulme J has explained the experience on which the Crown's case that the Senior Constable had the expertise which rendered his evidence both relevant and admissible under s 79 rested. That section provides that the opinion rule does not apply to opinion evidence which is based on a person's specialised knowledge 'based on the person's training, study or experience', where the opinion 'is wholly or substantially based on that knowledge'.

[105] All that the Senior Constable had done, in the performance of his duties, which on the Crown's case resulted in his claimed specialised knowledge and the formation of the opinions about which he gave evidence, was not, as RA Hulme J has explained, able to be replicated by the jury. In the result, I too consider that his evidence was correctly admitted, as it was both relevant to what was in issue at the trial and admissible under s 79, given the experience on which his opinions rested."

1. In any event, the issue was not determined by the learned trial judge on the basis of the evidence of Mr Reeves and/or Mr Jarman, expert or not. His Honour may have found that the state of the evidence was that there was no visible evidence of a flashover event, but he reasoned that might be explained by the passing of time as much as suggesting there was not such an event.
2. As to the question of whether there should have been evidence of damage to the internal windings of the transformer, his Honour held that it could not be resolved. Mr Gillespie's opinion was that a surge would cause damage to the internal windings of the transformer, and Mr Piper disagreed opining that there was insufficient evidence to determine that issue and that as damage is related to the magnitude and duration of the surge, it is conceivable that the surge could pass through the LV windings without damage.
3. The learned trial judge concluded that "the evidence led by the plaintiff goes no further than to establish that it [a flashover event] is possible." He said "[t]he Court finds that the existence of these facts is not proved; it is mere conjecture." To my mind, the real matter for consideration here is not whether Mr Reeves and Mr Jarman had relevant expertise but whether his Honour was justified, in a circumstantial case, in dismissing the establishment of a causal possibility as "mere conjecture", not capable of proving the possibility.
4. In my respectful opinion, his Honour was not so justified. As already noted, Porter J said in Langmaid (above) at [123]:

"[123] Expert opinion of a possibility can be used as circumstantial evidence, and a finding of factual causation may be made where the expert evidence 'does not rise above the opinion that a causal connection is possible'; the evidence will be sufficient if, but only if, the materials justify an inference of probable connection: Fernandez v Tubemakers of Australia Ltd [1975] 2 NSWLR 190 per Glass JA at 197. See also Seltsam Pty Ltd v McGuiness (2000) 49 NSWLR 262 per Spigelman CJ at 274 - 275 [79] - [83] ..."

1. The possibility, established by Mr Reeves' concession, that a flashover occurred and left no, or no lasting, visual evidence, is yet another "strand in the cable" of the totality of evidence going to causation. Before adjudging that possibility as "mere conjecture" and therefore of no value, his Honour ought, again with great respect, have had regard to all of the other circumstantial evidence relevant to the appellant's hypothesis that because of the distance between the high voltage (HV) bushing and the low voltage (LV) conductor, resulting from the placement of the transformer and the location of the LV conductor, a surge of electricity "flashed over" between the two, forcing the surge onto the LV system.
2. In my opinion the learned trial judge was wrong to have rejected the "lay" evidence as inadmissible or of no value and, having reached the view as to the "expert" evidence as to causation by a flashover event, that it "goes no further than to establish that it is possible", he ought to have then assessed that possibility by reference to the other circumstantial evidence. His Honour, should, in my view, have been alerted to the correct approach, by the evidence of Mr Piper (and Mr Page) later referred to by his Honour in isolation at [220] of his reasons, namely:

"[220] He considers his opinions supported by the fact that since 2012 key issues were fixed at the pole, which ensured the provision of additional insulation on the active 'a' conductor; raised the height of the transformer to create additional separation and installed a new earthing system for the pole. Since then he observed that the plaintiff has not suffered any further damage to its electrical equipment. He considers this result 'tells me' that damage was caused to the plaintiff's PLC in the manner he proposes. That mechanism is consistent with that identified by Mr Page."

1. Notwithstanding the observations I have just made, it is not appropriate, to consider at this stage in the review of the evidence and his Honour's reasoning, whether his conclusion on this issue is an operative or dispositive error for the purposes of the appeal. This is because his Honour, after seemingly leaving the first flashover hypothesis and moving on to the spark gaps hypothesis, later went on to consider a body of expert evidence which bore not only on that theory but also on the flashover hypothesis and the earth wire hypothesis. Accordingly I will return in due course to the question of his Honour's impugned conclusion of "mere conjecture" as to the flashover theory.

1. It is convenient to now consider the appellant's hypothesis concerning the separation of the earth wires running from the pole as, once again, while aspects of the body of evidence just referred to affect this theory, the learned trial judge made a discrete finding that he was not satisfied that "the location of the earth wires ... was established". Once again he concluded that the evidence led by the appellant went "no further than to establish that it is possible". And his Honour held, "[a]s such the existence of that fact does not go beyond conjecture, and is not sufficient to establish the matters on the balance of probabilities."
2. His Honour disposed of this hypothesis at [172]-[192] in the following terms:

"[172] Dealing first with the case based upon the resistivity of the earthing wire and the location of the earth wires, the Court acknowledges that the plaintiff's hypotheses are not mutually exclusive.

[173] This issue requires the Court to be satisfied that the plaintiff has proved on the balance of probabilities that the earthing system resistance was greater than 30 ohms on 10 December 2010, and the uninsulated earth wires were located less than two metres apart. Otherwise the mechanism through which it is argued a surge could be transferred into the low voltage system, is not established to have existed.

[174] Mr Burr's email, referred to earlier, is the source of the claim that a reading of 97 ohms was taken in 2012. It will be recalled that there is no evidence of the reading being taken, let alone of the method used.

[175] It is relevant that the reading relied upon, was taken some considerable time after 10 December 2010. It is relevant because of evidence from Dr D'Alessandro, an expert called by the defendant, which I accept. His evidence is that such reading fluctuates as the resistivity of the soil itself fluctuates. It follows that the reading is susceptible to variation, meaning different readings will be returned at different times. That evidence makes the applicability of a reading in 2012 to the actual reading (even the likely reading) in December 2010, uncertain at best.

[176] One of the issues that occupied the investigative process on this aspect was the possibility of excavation around the pole having interfered with the earth cables. (This was a relevant line of enquiry because the earth cables were located there.) I am satisfied that excavations were undertaken in the general vicinity of the pole before and after December 2010. Most of these appear to have been associated with flattening land for use as gardens. An external contractor (Beams Brothers) did most of this work. It is likely there was some excavation close to the pole because there was a black 'PVC' pipe near it. Asked about the black plastic pipe in the area of the pole Ms Brock said it was placed there by her husband in 2003. Mr Phillips' evidence about the excavations was relevantly the same as Ms Brocks.

[177] Mr Gillespie's evidence on this issue is material. It was that the excavation around the pole affected the resistivity of soil because it changed the density of the earth. Whilst the evidence of Mr Johnson [sic] on soil density is also material, it does not derogate from that essential point.

[178] The Court is not satisfied that the evidence of a reading taken in 2012 (assuming it to have been taken) can be relied upon for the purposes of making a finding about the matter in December 2010. It finds that resistivity is subject to fluctuation, and the excavations at or near the pole have influenced soil resistivity. The court is not satisfied on the balance of probabilities that on 10 December 2010, the earthing system resistance was greater than 30 ohms. The plaintiff has not proved a fact upon which it relies. It follows that the Court is not satisfied that the harm could have been caused by a mechanism which relies upon this fact.

[179] The location of the earth wires is the other aspect of the plaintiff's causation hypothesis which relies upon the earthing system of the pole. Its case is that these wires ran about 500mm below the soil at an angle of 120 degrees, and at their closest point they were 200-300mm apart. The standard required them to be 1.8 metres deep, at 180 degrees to one another, and be at least two metres apart.

[180] The defendant called Stephen Doolan. The Court accepts his experience of electrical installations enables him to express an opinion about such matters as the installation and configuration of wires and transformers. He worked for the HEC in June 1990. By 1995 he was an A grade linesman. In 2012 he attended at Markfield. He received instructions to go there from Mr Burr, perhaps Mr Baker, he was not sure. His job was to isolate the transformer and carry out the aerial component of the work. After completion of the earthing work, his task was to recommission the transformer.

[181] His evidence is that separation between a high voltage and low voltage earth wire is a minimum 2 metres. Earth wires are located in separate trenches. The earthing system for a transformer consists of earthing pins driven into the ground at intervals moving away from the pole. These pins are connected by copper wire. Earth wire is covered with PVC insulation to the point of the first pin. This pin is typically about one metre from the pole. Thereafter the wire is not insulated. It does not need to be, as it is moving farther away from the other earth wire. It continues moving away from the pole, connected to each pin as it goes. A reading is taken at each pin until a reading of 30 ohms is returned from the pin. A reading of 30 ohms is low enough for the transformer to be installed. The earth rods are approximately '6 feet' long and are designed to go '6 feet' straight down into the ground from a point about 46cm below ground level.

[182] As part of the job at Markfield in 2012 the earths were disconnected and removed from the pole. Two workmen dug trenches for the new earth wires. An excavator was required. Mr Doolan told the Court he noticed nothing about the infrastructure around the transformer that he would regard as 'untoward', and nothing unusual about the old earth wires. No earth pins were protruding above the finished level of the soil. The old earths were found and removed, but not tested.

[183] In 2016 Mr Doolan returned to Markfield. This was an investigative visit, to see if the old earth trenches and any of the earth componentry could be located. This action had been commenced by then. Once located, the wires were excavated. The process was video recorded. It showed the PVC water pipe installed by Mr Phillips, in the immediate area of the pole. Mr Doolan identified this as not something which is part of the normal infrastructure installed by the defendant. The old earth wires were covered in soil; some of the earth pins were out of position. At least one was horizontal. When or why that had happened he was unable to say, and he said it may well have happened that day.

[184] Mr Doolan's colleagues who attended with him in 2012 were called, and confirmed his evidence. They were Mr Reeves (who had installed the pole), Mr Baker and Mr Exton. None of them recalled carrying out any testing of the earthing system. It is likely it did not occur at that time.

[185] The plaintiff advances a number of matters it submits support an inference that the defendant's installation did not comply with the standards depicted in HEC Drawings B14731, and B12335.

[186] The plaintiff's case is that the 2016 video reflects the pre-2012 layout. It says that Mr Doolan's evidence is that there was an uninsulated LV conductor at the foot of the pole; that the video shows earthing rods covered in soil; and that the earthing rod shown in the vertical position was put into that position on that day. It contends that the lean of the electrode is in the direction of the pole; the remainder of it is underground; the video shows it 'generally parallel to the surface'; and it was 'standard practice' to bend these over when the soil became hard. It submits that because the purpose of the visit, and video, was for gathering evidence, the Court could properly conclude that any footage of the action of bending the rod was adverse to the defendant. I reject that submission.

[187] As well, the plaintiff relies on a photographic annexure to a report by FortEng, which appears to depict conductors 200mm from the base of the pole. If as the plaintiff submits, that is 300-500mm from the LV earthing system, then the closest point of separation is less than two metres. The depiction in the FortEng photo is not consistent with the evidence of Mr Doolan, or anyone connected with the installation of this pole (nor as to practices generally), or the observations made on the day the excavations were conducted. Furthermore the FortEng report discloses that FortEng's engagement was after the decommissioned earth rods were removed. The Court accepts the defendant's point that this casts doubt on the utility of these photographs as evidence for the point sought to be made.

[188] The location of the severed earth wire which points upwards is inconclusive. Not only might it have been placed into that position at the time of the excavation, but the evidence is that the relevance of the location of that wire is wholly dependent on the location of the LV earth. Mr Doolan's evidence is that there is awareness of the need for a two metre separation, and the placement of the second earth wire will be determined relative to the placement of the first: 'all our earthing-transformer earthing systems-we need a minimum separation of two metres. So if in fact we found we had already done ... the other earth ... and we had gone well out from the pole ... provided two metres was maintained it wouldn't matter.'

[189] The content of the still photograph taken from the video which was tendered from the 2016 excavations undertaken by the defendant cannot be said to indicate an arrangement which is contrary to the specification.

[190] Mr Doolan's evidence casts significant doubt upon the plaintiff's hypothesis as to the placement of the earth wire. The plaintiff's submission, is dependent upon a process of inferential reasoning that comes to an abrupt halt when it meets the evidence of Mr Doolan, and it fails again once the qualification required to be made about the FortEng photo is applied.

[191] The Court is not satisfied that the location of the earth wires, as alleged, is established. The evidence led by the plaintiff goes no further than to establish that it is possible. As such the existence of that fact does not go beyond conjecture, and is not sufficient to establish the matters on the balance of probabilities.

[192] It follows that the causation mechanism based upon the earths is not established: it is not open to the Court to find that the location of the earth wires could have caused the harm." (Emphasis added.)

1. The reference to an email written by Mr Burr was referred to by the learned trial judge earlier in his reasons at [133]-[135] as follows:

"[133] Mr Phillips gave evidence that at a meeting in December 2011 with representatives of the defendant, including a Mr Burr, there was a discussion about the transformer, including comments with respect to the proximity of the low-voltage wiring to the transformer. It was also suggested in that conversation that the high-voltage line coming into the transformer was too close to the outgoing line to the nursery. Mr Burr recalled this meeting. He said he looked at the transformer and the 'layout' of the pole. He observed what he considered to be evidence of excavations around the pole. He said he told the plaintiff's directors that it would be impossible to guarantee that the earthing system had not been impacted by any excavation because it is buried in the ground.

[134] He agreed to instigate a scope of works that would involve testing the earthing system. He also mentioned logging equipment being installed. The purpose of the loggers was to check the reliability of the supply to Markfield. He said he would look at the line running from Trevallyn power station to the property, to see if there was any potential issues with the feeder such as might be caused by birds straddling the wires or a tree touching the wire. The logging equipment was installed as promised though an issue as to the correctness of the installation is raised.

[135] In the course of these exchanges Mr Burr refers to an earth resistivity reading of 97 ohms at the pole. There is an issue, unresolved, about when the reading was taken, by whom, about its accuracy and its relevance. It is a matter relied upon by the plaintiff for its claim that the defendant's earthing infrastructure was installed incorrectly and was unable to function as intended, allowing high voltage electricity to enter the low voltage system. The Court will return to this issue."

1. The only return to the issue other than that set out above in [174] of his Honour's reasons was at [143] in the following terms:

"[143] That occurred on this analysis because electricity chooses the path of least resistance. It [the plaintiff] submits the resistance was set at 97 ohms, relying on the reference in the email from Mr Burr, referred to earlier. The resistance should have been no higher than 30 ohms, according to the HEC drawing B14731. At 97 ohms it did not offer the electricity the path of least resistance, so that the surge 'chose' the low voltage conductor rather than dissipating to earth."

1. In the notice of appeal the appellant asserts error in the treatment of this hypothesis by his Honour over and above the general contention that he erred in preferring the evidence of the respondent's experts over that of the appellant's experts without analysis of the reasoning underpinning the opinions of the expert witnesses, and over and above the contention that he erred in finding that there was not a high voltage surge event that damaged the PLC.
2. First it is said that his Honour erred in failing to find that on 10 December 2010, the earthing system resistance was greater than 30 ohms. Second that he erred in finding that excavations may have altered the earthing resistance around the pole. And third, that he erred in failing to find that the separation between the high voltage and low voltage earthing conductors/electrodes was less than two metres.
3. In my view the evidence of Mr Burr's email, and the relevance of an apparent reading of an earthing system resistance of 97 ohms taken in 2012 should not have been ignored by the learned trial judge. The email was introduced into evidence as a business record and was evidence of its contents. It is capable of being construed as conveying that the readings were taken before and after the earthing system was replaced on 20 January 2012 and that the HV earthing system reading was 97 ohms before and 17.6 ohms after the system was replaced. That evidence needed to be taken with Mr Page's evidence that, "to claim that a poly insulated pipe for a hose run through a small trench in the vicinity would have a large effect on the earthing system is questionable" and Ms Brock's evidence that the black pipe was installed in 2003 by Mr Phillips separately from the excavations.
4. It is unlikely I would think that a properly functioning high voltage earthing system of this type would give a reading of 97 ohms at any time, given that the evidence was that 30 ohms is the maximum resistance for such a system. To my mind his Honour ought to have been satisfied that the evidence of a reading taken in 2012 could be used as an item of evidence of potential influence in making a finding about the system resistance, only 15 months earlier, in December 2010. And he ought to have found that any excavations were unlikely to have significantly altered soil resistivity after the original installation of the earthing system.
5. In any event, his Honour's actual finding was that he was not satisfied on the balance of probabilities that on 10 December 2010, the earthing system resistance was greater than 30 ohms and the more pertinent matter is the significance of that finding. His Honour held that, "the plaintiff has not proved a fact upon which it relies." That much was true. The fact was not proved on the balance of probabilities. But he went on to find that, "it follows that the Court is not satisfied that the harm could have been caused by a mechanism which relies upon this fact." As I apprehend it, that statement, while valid syllogistic reasoning is a legal non sequitur, unless "the fact" was the sine qua non of "the mechanism". It was not. Mr Burr's email suggesting the apparent existence of a highly irregular reading, at a time prior to alterations to the equipment attached to the pole and the subsequent effective cessation of problems experienced by the appellant, was simply an item of evidence capable of constituting a strand in the cable of the appellant's circumstantial case as a whole.
6. To my mind, however, the more significant and potentially operative error on the issue on the earthing system hypothesis, is the learned trial judge's conclusion that, although "possible", the existence of the asserted fact as to the separation of the earth wires in the ground did not go beyond "conjecture". His Honour held at [191] of his reasons:

"The Court is not satisfied that the location of the earth wires, as alleged, is established. The evidence led by the plaintiff goes no further than to establish that it is possible. As such the existence of that fact does not go beyond conjecture, and is not sufficient to establish the matters on the balance of probabilities." [Emphasis added.]

1. That conclusion with respect, contains an error of approach no different to that which I have suggested was made in his Honour's approach to the evidence going to the possibility of the first flashover hypothesis. Having reviewed the relevant evidence I am unable to say that it was not open to his Honour to not find on the balance of probabilities that the earth wires were originally located less than two metres apart. (The video tendered by the respondent showing the site before its excavation in 2016 commenced with no earthing electrodes protruding from the ground, but omitted to show the actual excavation of the electrodes, and the photographic annexure to the report by FortEng of 21 January 2016, which showed conductors running horizontally and approximately 200mm from the base of the pole, was not unequivocal in the light of Mr Doolan's evidence that there was an awareness of the need for a two metre separation, and that the placement of the second earth wire would be determined relative to the placement of the first.) However, the possibility accepted by his Honour that the earth wires may originally have been located less than two metres apart, must be considered alongside all of the other circumstantial evidence going to causation. In particular it must be considered alongside the evidence that the appellant's excavations were undertaken in around about 2003 and that significant damage to household and other electrical equipment occurred before that date and continued to occur, at approximately the same rate, after 2003 and until 2012, when, amongst other things, the earthing system was replaced by the respondent. After the earthing system was replaced and additional insulation was provided on the Active 'a' conductor and the height of the transformer on the pole was raised, all problems effectively ceased. That is compelling evidence that the original earthing system was a potential irregularity responsible for the damage to the PLC on the potting machine. His Honour erred, with respect, in the way in which he approached the evidence relevant to this hypothesis.
2. Once again however, it is not appropriate to consider, at this stage in the review of the evidence and the learned trial judge's reasoning, whether his Honour's conclusion on this issue is an operative or dispositive error for the purposes of the appeal. This, as previously noted, is because his Honour went on, when considering the spark gap hypothesis, to consider a body of expert evidence which bore further on the earth wire hypothesis as well as the other flashover hypothesis. I will return to the question of his Honour's impugned conclusion of "conjecture" as to the placement of the earth wires in due course.

1. Turning now to the spark gaps hypothesis, once again, while aspects of evidence already referred to affect this theory, the learned trial judge dealt with this third hypothesis at the same time as he canvased a substantial body of expert evidence that led to his ultimate, impugned, conclusion at [259] of his reasons that "[t]he plaintiff has not established on the balance of probabilities that there was a high voltage surge event in December 2010 which damaged the PLC." His Honour's reasoning was as follows:

"[202] Turning to the spark gaps which on the plaintiff's case ought to have been set to 50mm in series (equivalent to two gaps in 25mm), the parties have agreed that the right hand spark gap was 60mm in series. The Court accepts that the left hand gap was 65mm in series. It is the plaintiff's contention that with the spark gap set at 60mm, it is possible for voltage to prefer the active 'a' conductor rather than the spark gap, irrespective of the effect of paint or too-high earthing resistance.

[203] The configuration of the spark gaps is established on the evidence. As such the Court is satisfied that there is a mechanism through which a high voltage surge could find its way to the low voltage 'pathway'. For the reasons following the court is not satisfied that the plaintiff has proved there was such event, and thus it has not proved that this arrangement of the spark gaps was a necessary element of the harm.

[204] It is admitted by the defendant that paint had been applied to an arc gap rod. However the thickness of the coating, and the type of paint used is not in evidence. That evidence is crucial to the plaintiff's thesis that the paint inhibited the operation of the transformer. The actual effect, if any, cannot be determined. The Court cannot be satisfied that in this respect there is a mechanism through which causation might be established. (The evidence is that this is how the transformers were supplied. I am inclined to think that a specialist manufacturer would not supply a transformer in a condition which inhibits that function, but I need not decide.)

[205] The plaintiff called Rayner Page and Gregory Piper, electrical engineers, to give evidence. It called Nicholas Johnson [sic] to give modelling evidence intended to demonstrate the way in which the failure to the PLC was caused by a surge current entering the property. The Court accepts their expertise in their respective disciplines.

[206] The defendant called Anthony Gillespie, as its expert electrical engineer. It called Dr Franco D'Allesandro as its modelling expert. He is an expert in lightning and surge protection. The Court accepts their expertise in their respective disciplines.

[207] The Court has had the opportunity to observe all these witnesses. The Court does not doubt the honesty, or independence of any of the experts. The court's observation of the experts is not material to its conclusion, nor is credit a matter relevant to the conclusion. The evidence was taken concurrently adopting an agenda prepared by the parties after an expert conclave, and managed by the court during the hearing. The process enabled the experts to put their opinions and to respond to the other experts, and to raise issues and questions about the opinions proffered. Further questioning by counsel was permitted but proved unnecessary to any significant extent.

[208] As between experts the Court prefers the evidence of Anthony Gillespie over Messrs Page or Piper, because of his particular qualifications and experience in electricity transmission, and the design and maintenance of PLCs in the electricity transmission business. His evidence is confirmed by, if that is necessary, and consistent with the modelling evidence before the Court.

[209] It prefers the evidence of Dr D'Allesandro to that of Nicholas Johnson [sic], based upon the former's qualifications, experience and publication of learned articles.

[210] The defendant also adduced evidence from Dr Muthumuni who undertook modelling of possible surge current and voltages travelling in accordance with each of the hypotheses advanced by the plaintiff. That evidence was received by consent. The court accepts it.

[211] What follows is necessarily a summary of the evidence. It is not possible to set out the evidence in a way which reproduces all of its content. In the final analysis the court is satisfied on the basis of the defendant's evidence, and supported by the modelling evidence of Dr Muthumuni that the plaintiff has not established a surge event of the magnitude alleged, or that the defendant's acts or omissions were a necessary element of the harm to the PLC.

[212] The narrative begins with Mr Page. He gave evidence that he was engaged by the plaintiff to investigate their electrical system, to identify possible causes of damage to equipment at the plaintiff's site. He gave evidence that in December 2011 he attended a meeting with Aurora and observed what he described as poor workmanship on the transformer installation and the low voltage conductor separation around the transformer pole.

[213] His evidence was that 'when I looked up at the pole, it was clear that there was inadequate air gap separation from the low voltage conductor, and there was no insulation on that conductor at the time. There was also a missing wildlife cover on the high voltage bushing closest to the high voltage conductor. After this meeting, Aurora proceeded to insulate the low voltage conductor and they then subsequently tested and replaced both the high voltage earth system and the low voltage earth system.'

[214] Later that same year he said the transformer was raised to increase the air gap separation of the low voltage conductor and the high voltage terminals of the transformer. He told the Court that testing in 2013 of the modified high voltage and low voltage earth systems 'showed the transferral of voltage from the high voltage earthing system to the low voltage earthing system under high voltage fault condition.' (He said these results were initially discounted because at the time it was understood that the PLC specifications were 240 volt AC when they were 24 volt DC. Upon that misunderstanding being corrected, the results were reconsidered as a possible cause of the mechanism which caused the failure of the PLC.)

[215] A critical issue in the question of causation is the magnitude of the surge. The evidence of Mr Page, and also Mr Piper, is that a recloser can produce a surge current of 4.6 pu. [4.6 times per unit voltage] It is their opinion this is sufficient for a flashover of both the spark gaps or from the bushing to the LV conductor. Mr Piper clarified his evidence in this regard by saying that 4.6 pu is the maximum surge measured in a study undertaken by Gupta and others under real world conditions, and not in a laboratory.

[216] Gregory Piper is lead electrical engineer with FortEng Consulting based in Queensland. For the purposes of his evidence he received three reports prepared by Mr Page, the Engrid report of 30 September 2017 and the FortEng report of 21 January 2016. He had a report from the defendant's witness, Mr Gillespie, dated October 2015. He viewed a video prepared by the defendant in 2015. He received several diagrams from the HEC relevant to the pole, and some recordings taken by the defendant's employees on 12 December 2017. He was provided with a photograph which he was told was taken on 12 October 2017 of one of three conductor joints on the low voltage lines supplied from the pole in question and supplying low voltage power to the property. He was told, and accepted that the same cable joints exist on the other two conductors supplying the property.

[217] The substance of Mr Piper's opinion is derived from the FortEng report of 21 January 2016. That report concludes that any surge exceeding 3 kA 48-20th of a microsecond in the pre-2012/2013 configuration of the pole would result in a surge voltage reaching the potting shed which exceeded the dielectric withstand voltage of the PLC unit. Mr Piper's opinion is that the most likely cause of damage to the PLC was a surge of high voltage electricity which bypassed the surge protection on the transformer and arced to the active 'a' conductor where it travelled to the PLC unit by one or more unknown paths 'that cannot be empirically determined'. He opines that the surge was able to bypass the surge protection on the transformer because the spark gaps on the transformer were not properly aligned; the spark gap electrodes were painted; the active 'a' conductor was too close to the HV bushing; and the resistance of the HV earthing system was too high.

[218] Mr Piper told the Court that a surge greater than 3 kA 48-20th of a microsecond is a standard surge modelled by electrical engineers; not uncommon in the electrical industry, and in his experience most electrical surges exceed this model. It is his opinion that such a surge could easily have occurred if vegetation caused a connection between the conductors upstream of the transformer, especially when the lines recloser operated multiple times before locking out. He acknowledged that under ordinary operating conditions it is impossible to know precisely the voltage and/or amperage of the surge when it reached a particular point in the line such as the transformer at Brocklands Nursery.

[219][ Mr Piper's opinion is that the configuration of the earthing system does not affect the accuracy of his hypothesis that electricity arced from the HV transformer bushing to the LV active 'a' conductor where the spark gaps were misaligned and the spark gap electrodes were painted. Each could bypass the three phase switch upon reaching the PC (near the potting machine). It could do this, in his opinion, by jumping across the electrical contacts, and this would be so whether it was in the on or off position. (On this basis Mr Piper rejects Mr Gillespie's opinion that the fact that the three phase switch supplying power to the potting machine was in the off position, would have stopped a fast front high voltage surge).

[220] He considers his opinions supported by the fact that since 2012 key issues were fixed at the pole, which ensured the provision of additional insulation on the act of 'a' conductor; raised the height of the transformer to create additional separation and installed a new earthing system for the pole. Since then he observed that the plaintiff has not suffered any further damage to its electrical equipment. He considers this result 'tells me' that damage was caused to the plaintiff's PLC in the manner he proposes. That mechanism is consistent with that identified by Mr Page.

[221] Mr Gillespie commented on each of the hypotheses advanced by the plaintiff, some of which are not relevant in view of the Court's findings of fact.

[222] Relevant to the magnitude of a surge at the potting machine, albeit in terms of a mechanism the Court has discounted, Mr Gillespie told the Court that if there was a switching surge that entered the HV earthing system at the pole, and it was coupled and transferred to the LV earthing system through the soil, then a switching surge would occur on the LV neutral. Referring to Dr D'Allesandro's evidence on this point (and to the same effect), Mr Gillespie opined that the magnitude of a transfer between the HV earthing and LV earthing would be small even on a worse-case scenario, where the closest separation between the two was only 300mm, and regardless of voltage. It is his opinion that there is significant attenuation of the voltages on the LV neutral between the house and the potting shed, which would mean that the largest magnitude of the switching surge would occur at the house (not the potting shed) and it would be attenuated as it travelled through the nursery and to the PLC.

[223] On this basis he opines that the 230 volt weighted electrical equipment would be expected to fail at less than half the value for the PLC when subject to an over voltage switching surge. As such, it was his opinion that the computer and domestic electrical equipment in the house would likely fail before the PLC in the potting shed.

[224] Given that equipment (in the house) did not fail, then the PLC did not fail due to a switching surge, in his opinion.

[225] Mr Gillespie told the Court that if there had been a flashover of the spark gaps shunting the surge to the HV earth, then 'power follow current' would be expected, and that such current would create an earth fault which would blow the fuse. Since there was no evidence to suggest that the fuse had blown since December 2010, there was no flashover of the spark gaps on that day, in his opinion.

[226] Further, in his opinion, power follow current would create visible marks on the spark gap, and there were none. Mr Gillespie acknowledged a visible mark on one of the rods of the spark gap, but, because there was not a fuse blown on 10 December 2010, it was his opinion that the spark gap flashover which caused that mark occurred prior to 10 December 2010.

[227] It is accepted by the plaintiff that the fuses on the pole have not blown. (They are drop fuses which means that if they blow they will drop down enabling that fact to be evident.) Mr Piper expresses no surprise that the fuses had not blown, because, he says, they are designed to blow in fault circumstances when energy travelling through them causes them to heat up and disintegrate. It is his opinion that during the fast moving surge event of the kind he considers caused damage at Brocklands, the surge would pass through the fuses without blowing them because they would not get hot enough;. 'Fuses are fault protection, not surge protection.'

[228] Based upon Mr Johnson's [sic] experience in HV testing, the plaintiff submits that power follow current would extinguish when the voltage reaches a zero, and that this can occur in 10 milliseconds at normal power frequency of 50 Hz, to mean that at 10 1000ths of a second, the power follow current extinguishes at 0.3 seconds before the fuse would blow. The plaintiff submits that Mr Johnson's [sic] opinion is supported by the references referred to by Messrs Page and Piper, and the result is that even if power follow current does occur as Mr Gillespie asserts, it extinguishes (or is quenched, as it was put) before a fuse could blow.

[229] I prefer the evidence of Mr Gillespie on this issue.

[230] In relation to the mechanism which proposes that a flashover from the HV bushing to LV conductor 'a' enters to secondary winding of the transformer and comes out of the LV neutral and into the house and nursery, Mr Gillespie's opinion is that the maximum switching surge of 35 kV to 55 kV is insufficient to flashover the 110mm air gap between the HV bushing and LV conductor 'a', as 98 kV is required to flashover that air gap. As such if there had been a flashover between the HV bushing and the LV conductor 'a' then power follow current would be expected. This takes the matter back to the fuses, which Mr Gillespie asserts should have blown. Since they did not, in his opinion there was no flashover between HV bushing and LV conductor 'a'.

[231] The same point is made by Mr Gillespie in respect of the mechanism which proposes a flashover from the HV bushing to the LV conductor 'a' and into the house and nursery. In respect of this mechanism, the power follow current would create visible marks on the spark gap. Because the fuse has not blown since 10 December 2010, Mr Gillespie's conclusion is that the gap flashover occurred before that date.

[232] He adds that if there was a switching surge that entered the house on the LV conductor 'a' the combined effect of the line impedance of the LV wiring and the load impedances would cause attenuation of a switching surge. This would mean that the largest magnitude of the switching surge would occur at the house and it would then be attenuated as it travelled to the PLC. In those circumstances, electrical equipment would be expected to fail along the way. This would occur before the PLC. Since it did not, it is his opinion that the PLC did not fail due to a switching surge.

[233] The plaintiff asserts that Mr Gillespie speculates 'without providing reasons'. The Court is urged to approach Mr Gillespie's opinion with a level of circumspection given 'the demonstrable level of rigidity in his opinions', notwithstanding new evidence becoming available over time.

[234] Mr Gillespie properly acknowledged the need to alter aspects of his opinion based upon additional information, as did Mr Page. It is perfectly reasonable for the plaintiff to criticise Mr Gillespie's opinion, but the proposition that his opinion was inflexible is rejected.

[235] To the extent that reliance is placed upon the proposition that Mr Gillespie is the only expert witness who expressed a view to the effect that there was no causative link between the event relied upon by the plaintiff and the damage to the PLC, nothing turns on it. It is not a numerical contest.

[236] I accept the defendant's submission in this respect. Furthermore, Dr Muthumuni's unchallenged modelling supports the conclusions expressed by Mr Gillespie.

[237] Turning to Dr D'Alessandro's evidence, his opinion is that it was likely that when the recloser operated there would have been minimum load on the power system. He opines that the voltages reaching the potting shed were well below 1,000 volts.

[238] But in any event he said that a surge of up to 1,392V was unlikely to have caused any damage to the PLC, notwithstanding its steady state 500V dialectic withstand voltage. That is because electronic equipment actually has a far higher withstand voltage for brief transient over-voltages.

[239] The substance of his evidence with respect to causation is that, in respect of any of the mechanisms posited by the plaintiff, the voltage was not sufficient to damage the PLC when allowances are made for the duration of the switching impulse. 'The PLC has a rating of 500 volts AC for one whole minute, but an impulsive surge, going down the line, lasts a much shorter time than that and therefore, you get a much higher voltage withstanding on the equipment.'

[240] Dr D'Alessandro reviewed his conclusion after considering the analysis by Dr Muthumuni. It did not alter the conclusions contained in the original modelling report which were to the effect that the PLC is unlikely to have been damaged by a switching surge on incoming conductors. Dr D'Alessandro set out his calculations to support those conclusions.

[241] Using Dr Muthumuni's results, Dr D'Alessandro modelled the surge propagation from the transformer into the plaintiff's Low Voltage installation through to the PLC. He concluded that there was insufficient voltage on any of the mechanisms to cause damage to the PLC.

[242] The modelling evidence of Dr Muthumuni was tendered with the consent of the plaintiff, and without the need for Dr Muthumuni to be called. Dr Muthumuni undertook PSAD based switching studies to estimate the maximum switching surge voltage and current at the 22 kV pole mounted transformer as a result of a recloser operation about 14 kilometres away. Dr Muthumuni is the lead developer of the PSAD program, which is used by utilities in Australia and internationally. The Court accepts his expertise in his field. The input data relied upon by Dr Muthumuni was admitted by consent. His expertise is not challenged, nor is his use of the PSAD program to carry out his modelling. Whether or not the plaintiff perceived a forensic advantage in not having Dr Muthumuni appear to have his evidence tested, is irrelevant to the Court's conclusion that his evidence is directly relevant to the Court's ultimate conclusion. Its relevance is not in issue, and the analysis, assumptions and conclusions within it have been neither challenged nor tested in cross-examination.

[243] The plaintiff's challenge to the utility of the modelling undertaken by Dr Muthumuni relates to the following matters:

(i) The network maps and information provided to Dr Muthumuni are not in evidence.

(ii) That his report discloses reliance upon one map of the network (which appears within his report and is marked 'figure 1') and that there is no evidence he relied on other maps.

(iii) That the network map relied upon by him is undated and it is unknown whether the map represents a current network layout or that which was in place on 10 December 2010.

(iv) That it contains handwritten information likely added for the purpose of litigation, with no evidence who added it, let alone their qualifications or experience, or the source of the information.

(v) There is no evidence the network has been constructed in accordance with the design drawings provided, and there is no evidence led by the defendant that the network line had been audited for accuracy against the map provided to him.

(vi) The report does not disclose whether he attended to compare the model with the built form of the network, or engaged anyone else to do that.

(vii) The network map cannot be tested by the plaintiff because it is unable to access the defendant's network.

(ix) Dr Muthumuni was provided with a cross-arm diagram but not with other diagrams such as fuse arrangements, branches, circuit breakers, or transformer arrangements. It is submitted that it is possible that the HVDC model considers Canadian distribution standards which differ from those in Australia.

(x) The evidence of the length of the line is contained in documents tendered by the defendant in respect of which there is no evidence of field verification.

[244] In respect of the modelling and the factual matters relied upon, the plaintiff submits:

(i) The only evidence of the types of conductor used between the Glengarry recloser and the transformer is contained in the unattributed handwritten notes in figure 1.

(ii) There is no specification of which conductors have been modelled: it is not specified whether one conductor for the whole model or different types of conductor have been considered. It is submitted that if the former, then the model fails to reflect that which exists in the field, and if it is the latter, the different conductors used are now shown. It is submitted that this failure to properly disclose underlying assumptions reflects the weight which can be given to the modelling.

(iii) The network maps only show the network in the immediate vicinity of the recloser and the pole, suggesting the modeller has not taken into account other assets of the network. (The implications of these variations were the subject of evidence from Mr Page who said the nearby Brocklands quarry operating with large machinery may have an effect on surge voltage. It is put that Dr Muthumuni was not provided with this information, and did not validate the information on site so that he could not take it into account in the model that he has prepared.)

(iv) The HVDC model shown at figure 3 in the modelling only models the line between the recloser and Brocklands. Since the network expands across the entire State, and the network in the area is far more expansive, the modelling is deficient. It is further submitted that Dr Muthumuni does not state that he considers the level of information with which he has been provided to be sufficient, although this is implicit, it might be thought.

(v) The modelling fails to model four surges caused by a recloser operating four times in quick succession, an aspect the plaintiff's experts consider critical to the modelling.

(vi) There is no consideration of surge reflections caused by the recloser operation four times.

(vii) The modelling assumes a one second recloser operation and the actual specifications are not known and have not been provided.

(viii) The type of recloser has not been provided to the modeller to consider whether it is a variable that needs to be taken into account.

(ix) The modelling fails to take account of the way in which the recloser was activated by a tree fallen over the line and therefore a fault that was occurring further along the line in an area that was not being modelled, while the recloser was operating, was not considered.

(x) The HVDC report discloses the modeller has not referred to the specifics of the transformer or the orientation of the pole in question; there is no suggestion that he has referred to photographs of the pole or the transformer.

(xi) Dr Muthumuni was not provided with material which disclosed the recloser setup.

(xii) The map (referred to as figure 1) refers to a typical pole height of 8.85 metres, whereas the pole in question is 12 metres. The plaintiff contends that after burial in accordance with the requisite standard requiring 1.8 metres below ground, the pole height would be 10.2 metres, not 8.85 metres. This is said to be a parameter for the modelling, the impact of which is 'unclear'.

(xiii) There is no disclosure in the report as to whether factors such as magnetic field density or rain humidity and air pressure may have an effect on the modelling and thus the results.

(xiv) The loading on other assets on the network is not disclosed, raising the question of whether there are exceptions to the rule that generally the load on the LV side acts to link with the transient over voltage.

(xv) Finally, it is submitted that Mr Page opined that Dr Muthumuni had failed to properly model the Low Voltage system connected to the transformer in accordance with Australian Standards.

[245] The plaintiff submits that the Court cannot be satisfied that Dr Muthumuni's modelling actually represents the worst case scenario as he stated in his preamble. It says that the Court should reject the defendant's submission that the modelling reflects the makeup of the defendant's network. It submits that accurate modelling must include a proper survey of the line to determine whether the network maps are in accordance with reality; validation of the model against field testing of the network is required; a model that takes account of the precise operation of the recloser, including how many times it operated and the time taken to reclose is required.

[246] The plaintiff also submits that full knowledge of the technical specifications of the recloser is necessary, as well as information with respect to the actual types of conductor, the actual length of the line, the correct pole height, and the extent of the network and the impact of that network and its characteristics on the modelling. It is submitted that the modelling should take into account why the recloser operated, and deal with phase faults in the correct order. It is submitted that the defendant has failed to provide an accurate model, has done so at the last minute, and produced a 'woefully inadequate model in an attempt to exculpate itself from liability'.

[247] As a result the modelling ought to be given no weight because the Court cannot be satisfied on balance that the information provided to Dr Muthumuni was correct and accurate, and that the model reflects the network as at 10 December 2010, and that it models what is known to have occurred on that day.

[248] The issues the plaintiff raises in respect to this evidence, and the methods have not been put to Dr Muthumuni. He was not required by the plaintiff for cross-examination, though made available. The relevance, and importance of many of the matters raised to the utility of the opinion to the Court in reaching a conclusion on causation, are very much matters for expert judgment, themselves. The court observes that as an expert Dr Muthumuni comprehends the matters relevant to his modelling, and necessary to complete it. It might reasonably be supposed he obtained what he needed for his purpose. But the plaintiff's failure to test his evidence by investigating any or all of these issues cannot be ignored in dealing with its objections. The court is satisfied having analysed the evidence of Dr Muthumuni and considered it in the context of the expert evidence, that it adopts appropriate methodology, based on correct inputs. A careful analysis of his report discloses appropriate allowance for relevant variables, such that the Court is satisfied that this modelling is relevant, accurate, material and useful, and can be applied to the case. The plaintiff's submissions are without substance. They are with respect more in the nature of advocacy, a series of challenges the plaintiff preferred not to put to the author of this evidence.

[249] One other issue raised by the plaintiff requires mention. It urges rejection of the evidence, upon the somewhat semantic proposition that because Dr Muthumuni expressed an opinion that it was 'unlikely' that the amplitude of the surge voltage would be sufficient for a flashover, as distinct from using the word 'impossible', the plaintiff's hypotheses as to causation remain possible and thus, subject to evidence, capable of being established as more probable than not.

[250] At the outset it may be observed that the notion of something being impossible is beyond the ability of any of the experts to opine. In the Court's view Dr Muthumuni's use of the word 'unlikely' is synonymous with 'improbable'. Improbable is synonymous with unlikely, and engages the language of probabilities in a context where it is to the probabilities the Court must turn its mind.

[251] Turning to that evidence, the conclusion expressed by Dr Muthumuni relates to each of the hypotheses advanced by the plaintiff. Dr Muthumuni referred to scenario A, scenario B/C and scenario D. The plaintiff's case has been expressed in terms of scenarios A, B and C. It is helpful to identify the scenarios as explained by Dr Muthumuni in his report. He describes scenario A as a switching surge which reaches the transformer 22 kV bushing and enters the High Voltage earthing system via coupling, without the bushing spark gaps flashing over. Scenario B/C involves a switching surge reaching the transformer and flashing over from the HV 22 kV conductor to the low voltage (LV) Active conductor.

[252] Scenario D involves the switching surge reaching the transformer and the spark gap firing, sending energy into the HV earth.

[253] Dr Muthumuni's method involved a sensitivity analysis being carried out to determine the impact of HV and LV earthing resistance on transient voltages and currents. The earthing resistance values considered were:

[254] For each scenario, loading conditions on the LV side of the transformer were studied:

[255] Dr Muthumuni used the PSAD model to investigate the switching frequency over-voltages due to the operation of the recloser. The Power System Technology Centre, a division of the Manitoba Hydro International Limited operation, performed switching transient over-voltage studies to determine the impact of a 32 kV recloser operation on transient voltages on the Low Voltage (480 v) of a transformer. The pole mounted transformer High Voltage side is supplied with a two phase 22 kV connection. The Low Voltage side is a 480 V centre tap winding. The transformer is configured in accordance with that at the nursery, with a separate HV and LV earthing system.

[256] Dr Muthumini's modelling gives values of the expected voltage and current of the transformer for each of the plaintiff's proposed mechanisms on the HV earth, LV active and LV neutral conductors. His modelling applied details of the actual HV feeder from Glengarry recloser to the transformer, including its different section lengths and conductor types to model the network impedance and to represent the propagation of the surge in the Brocklands context.

[257] Dr Muthumuni reported that the maximum voltage recorded in his modelling across the HV bushing air gap was 36.73 kV. He concluded that 'based on typical air breakdown strengths, it is unlikely that the amplitude of the surge voltage would be sufficient for the air gaps to flashover'.

[258] This evidence, Dr D'Alessandro's evidence and modelling, and the evidence of Mr Gillespie, renders the plaintiff's hypotheses no more than speculative.

[259] The plaintiff has not established on the balance of probabilities that there was a high voltage surge event in December 2010 which damaged the PLC. [Erred in finding at [259] that there was not a high voltage surge event that damaged the PLC.]

[260] The plaintiff has not established that the configuration of the pole was a necessary element of the harm to the PLC. It has not established factual causation to the standard required, and described in Langmaid (above) and the cases cited there, and repeated earlier in these reasons. In the language used by Blow CJ in Langmaid, and at the risk of repetition, the Court does not feel an 'actual persuasion' and it declines to draw the inference that the harm to the PLC was caused by the defendant." (Emphasis added.)

1. In the notice of appeal the appellant asserts error in the treatment of this third hypothesis by his Honour over and above the general contention that he erred in preferring the evidence of the respondent's experts over that of the appellant's experts without analysis of the reasoning underpinning the opinions of the expert witnesses and over and above the contention that he erred in finding that there was not a high voltage surge event that damaged the PLC.
2. First the appellant contends that his Honour erred in failing to find that the agreed distance of separation of the high and low voltage conductors could give rise to a flashover event. Second it contends that he erred in respect of the evidence of Dr Muthumuni:

In considering it on the basis that that it was tendered by consent [210] when it was not [T525 - 553], and;

At [248] in disregarding the absence of a proper basis for his opinion because the plaintiff did not put the shortcomings listed at [243 and 244] to Dr Muthumuni."

1. As I apprehend it, the learned trial judge's conclusion that Dr Muthumuni's evidence, Dr D'Alessandro's evidence and modelling, and the evidence of Mr Gillespie, rendered "the plaintiff's hypotheses no more than speculative" was a rolled up conclusion as to the spark gaps hypothesis and as to his Honour's similar conclusions, already noted above, as to the first flashover event hypothesis and as to the existence of the asserted fact as to the location of the earth wires and the associated hypothesis. This rolled up conclusion is, with respect, an error no different to those which I have suggested as to his Honour's approach to the evidence of the first flashover hypothesis and the earth wires hypothesis. Before any of them could be dismissed as non-probative speculation, the established possibility that he accepted, correctly in my view, that those hypotheses were correct, must be considered alongside all of the other circumstantial evidence going to causation.

1. I return then to the errors I have identified in order to consider whether they are, on a proper analysis, either alone or in combination, operative or dispositive errors when considered in the light of the totality of the evidence relied upon by the appellant for its circumstantial case.
2. The first observation I would make is that it is clear from the passage at [248] of the learned trial judge's reasons that his Honour placed great weight on Dr Muthumuni's evidence modelling the surge wave created by reason of the operation of a recloser. Notwithstanding the appellant's extensive criticism of it, his Honour regarded Dr Muthumuni's Manitoba Modelling report as the glue that bound Dr D'Alessandro's evidence and the evidence of Mr Gillespie together into a trinity which dispelled the appellant's hypotheses.
3. However, in my respectful opinion his Honour was not justified in dismissing the appellant's criticisms of Dr Muthumuni's methodology and inputs in the manner in which he did. There were 15 separate criticisms put forward by the appellant and adumbrated by his Honour in the passage from his reasons set out above. Most of them, but particularly those listed at [244] (ii) and (iv) - (ix) of his reasons, give me cause for concern when taken with Mr Gillespie's evidence that "I think that he [Dr Muthumuni] was supplied with data for the network and he modelled it to give an estimate of the maximum switching surge voltage and the currents at the transformer. That was the intent and that's what he produced", and taken with Dr Muthumuni's own statement in his report that it was "unlikely" that there would be a flashover - not that it was impossible. [Emphasis added.]
4. Nor, with respect, was his Honour justified in his reliance, for apparent fortification of his confidence in Dr Muthumuni, on his Honour's view that the issues the appellant raised had not been put to Dr Muthumuni because the witness "was not required by the plaintiff for cross-examination, though made available" and that the criticisms were advocacy.
5. It matters not that the appellant's criticisms were "advocacy". Counsel's criticism of evidence in a circumstantial case, is, as was observed by Lord Cairns in Bellhaven v Stenton Peerage (above), at 279, advantageous and "wholesome".
6. Nor, with respect, was it entirely contextually correct for the learned trial judge to note that Dr Muthumuni's evidence was tendered "with the consent of the plaintiff, and without the need for Dr Muthumuni to be called" or that the appellant "preferred" not to put its criticisms to Dr Muthumuni, despite him being made available for cross-examination, or to refer to the modelling evidence as "unchallenged".
7. The following passage from the transcript of the trial sets out the way in which Dr Muthumuni's evidence was introduced, after written objection by the appellant:

"HIS HONOUR: If the evidence is relevant which is conceded and if the need for the modelling is a product of your expert articulating a specific position different from that which was previously assumed then prima facie the evidence should be allowed to be led subject to prejudice and I understand the claim to prejudice - and I have said this before in this trial - I think the prejudice can be cured. I think that the court would be embarking upon a dangerous course if it simply ignored relevant evidence.

MR READ SC: I hear what your Honour says and it was necessary for us to be very open about this. The plaintiff's position is this trial must finish this week. The plaintiff does not have the means to continue with this trial beyond this week.

HIS HONOUR: You are not going to get a decision this week.

MR READ SC: No, no, no. I understand that, your Honour, but it has got to finish this week. The experts are here. Counsel is here. The costs are all being incurred.

MR READ SC: From the plaintiff's position we do not request an adjournment, your Honour. That's our position and we make it very clear and we're very honest about it.

HIS HONOUR: Yes; and that goes to the question which is the supplementary question. If I allow the evidence is that evidence to be led before the concurrent evidence which I understand to be the defendant's request or can it be-

MR READ SC: It is not to be led at all, your Honour. That's it. That's the evidence.

HIS HONOUR: It is going to be tendered, isn't it? You're not going to cross-examine.

MR READ SC: It will just be - it will be D, whatever it is.

MR READ SC: That's why the plaintiff takes this position because it is in the very tight spot in which it finds itself. Now, your Honour, I don't want to - I will risk it but the change of position relates to the amps. It was Mr Gillespie who first proposed 138 amps. That was then responded to by Mr Piper and he has got a different figure. That's the change. Excuse me, your Honour. Yes; and it was responded to on a what if situation. Presuming Mr Gillespie is correct then this is what we say it is. So it's not though it's asserting - asserting a new position, your Honour, his position has always been, it's entirely possible for a surge - for a sufficient surge to be - to come from the recloser, that's the position, but assuming Mr Gillespie's correct, then the figures by reason of various bits of - by various literature, come out much higher than Mr Gillespie says. It is purely and simply in reply to his assertion, your Honour, it is not a change of position, that's - that's the core point.

HIS HONOUR: Well - well I disagree, I think it is a change in position, it may be responsive to some other change, but it nevertheless, is a change of position, because he's gone from the rule of thumb and the assumption based upon a rule of thumb approach, to expressing a view, which is inconsistent with the so called rule of thumb and he's done that on the 23rd of April.

MR READ SC: No, no with respect, your Honour, he hasn't. He's accepted the rule of thumb, the rule of thumb is still inherent in Mr Gillespie's 138 amps, so the rule of thumb is the underlying assumption, that's that remains. Mr Gillespie from the rule of thumb (inaudible) loads 138 amps, Mr Piper, calculates a different figure, that - that's the number, your Honour.

HIS HONOUR: All right. Well I've been in-precise, but I think I've summarised -

HIS HONOUR: - the position correctly, subject to that qualification that you've just made. Look I understand your position, but the evidence is relevant, that fact's conceded, I'm prepared to give your client an opportunity, if it claims prejudice to deal with the prejudice, if that invitation's not taken up, that's a matter for the plaintiff, but I don't think that in the proper exercise of my discretion, I can refuse the evidence that's proposed to be led and so I overrule your objection.

MR READ SC: Yes, I understand that, your Honour, the plaintiff, I - I understand the invitation for an adjournment, your Honour, the plaintiff is not in a position to take that up.

MR READ SC: The prejudice is, on our submission, incurable.

1. Notwithstanding modern day deference to principles of case management, it cannot, in my view, be said that the learned trial judge erred in the exercise of his discretion to admit the evidence despite it extending the length of the trial beyond the appellant's expectation and capacity if Dr Muthumuni was to be called. However, equally, it is somewhat harsh to suggest that the appellant "preferred" not to cross-examine the witness despite being given the opportunity to do so.
2. As to the appellant's submission to the trial judge in closing that the respondent had not proved a number of the factual assumptions that were apparently relied upon by Dr Muthumuni, Blow CJ, with whom Wood and Brett JJ agreed, explained in Langford v Tasmania [2018] TASCCA 1 that the majority view in Dasreef Pty Ltd v Hawchar [2011] HCA 21, 243 CLR 588, decided only that the lack of proof of an underlying fact went to weight and not to admissibility.
3. On my own examination of the Manitoba Modelling report, I am unable to replicate the learned trial judge's confidence that Dr Muthumuni's methodology and input data was self-evidently "accurate, material and useful". In my view, unexplained and untested, Dr Muthumuni's evidence does not have the internally obvious and reliably decisive quality attributed to it by his Honour.
4. It must be remembered that the historical evidence as to the correlation between damage to the equipment at Brocklands and the operation of the respondent's protective devices was that damage only occurred during some power outages and not others. It is reasonable therefore, to suspect, as was submitted by counsel for the appellant in closing submissions at trial, that the variable giving rise to the relevant phenomenon might be something apparently insignificant, for example, the number of times the recloser operated or what caused the recloser to operate. In such circumstances, reliance on a model other than one that took into account the precise operation of the recloser, including how many times it operated and the time taken to reclose, and absent knowledge of the technical specifications of the recloser, must, to my mind, be regarded as fraught.
5. In the final analysis it is my view that Dr Muthumuni's modelling was only, as Mr Gillespie said, an "estimate", and even taken at its highest it was, in Dr Muthumuni's own words, merely, "unlikely" that the amplitude of the surge voltage would be sufficient for a flashover, as distinct from "impossible" or even "inherently improbable". The appellant's hypotheses as to causation did indeed remain "possible" and, coupled with other circumstantial evidence, remained capable of establishing factual causation as more probable than not.
6. I respectfully disagree with the learned trial judge's view that Dr Muthumuni's use of the word "unlikely" was synonymous with "improbable" in the sense, as his Honour put it, that it "engages the language of probabilities in a context where it is to the probabilities the Court must turn its mind." To my mind Dr Muthumuni's methodology and particularly his questioned inputs, while falling well short of rendering it inadmissible, ought, for the reasons advanced to his Honour by the appellant, to have been treated cautiously. It did not alone, or in conjunction with Mr Gillespie's and/or Dr D'Alessandro's evidence, dispel the appellant's circumstantial case for factual causation. Indeed, on one set of assumptions made by Dr D'Alessandro his conclusion, as I apprehend it, was that voltage sufficient to damage the PLC was produced.
7. Next, in relation to each of the possible mechanisms of a switching surge occurring on the LV neutral, the possible mechanism of a flashover from the HV bushing to LV conductor 'a' entering to secondary winding of the transformer and coming out of the LV neutral and into the house and nursery, and the possible mechanism of a flashover from the HV bushing to the LV conductor 'a', Mr Gillespie's evidence was that a power follow current would be expected, which he asserted should have blown a fuse or fuses at the transformer. Since there was no blown fuse, in his opinion there was no surge. Mr Piper's opinion on the other hand was that the fuses had not blown because they are designed to blow in fault circumstances when energy travelling through them causes them to heat up and disintegrate. It was his opinion that during a fast moving surge event of the kind he considered caused the appellant's damage, the surge would pass through the fuses without blowing them because they would not get hot enough. His view was that fuses are "fault protection, not surge protection." As to this contest of ideas, I note that historically at least six events evidence a correlation between the operation of the respondent's protective devices and damage sustained to the appellant's electrical equipment and the evidence was that the fuses had not blown since 1998.
8. Perhaps his Honour should have accepted the appellant's expert evidence. I find Mr Piper's opinion compelling. But at best from the appellant's perspective the combined expert evidence it adduced demonstrated a causal connection between the equipment on the pole and the damage to the PLC, whilst the respondent's expert evidence neither showed such a connection to be impossible or inherently improbable, nor established that it was less likely another reasoned probable cause. The precise magnitude of surge voltage the PLC would withstand was, on the evidence, simply unknown, especially when the line recloser tripped multiple times before locking out. At worst from the appellant's perspective, the expert evidence on either side was not capable of establishing causation or negating it. In those circumstances, in either the best or worst case scenario, the other circumstantial evidence to which I have referred was, to my mind, sufficient to establish factual causation on the balance of probabilities. Indeed it was, in my view, sufficient without any expert evidence. Aided however, by the "possibilities" accepted by the learned trial judge as at the very least to be derived from the expert evidence, the other strands in the cable combined to create what I regard as an overwhelming circumstantial case.
9. The same analysis can be applied to Mr Gillespie's view that if there was a switching surge that entered the house on the LV conductor 'a', the combined effect of the line impedance of the LV wiring and the load impedances would cause attenuation of a switching surge, which would mean that the largest magnitude of the switching surge would occur at the house and it would then be attenuated as it travelled to the PLC, so that electrical equipment would be expected to fail along the way. Since it did not, it was his opinion that the PLC did not fail due to a switching surge. Even leaving aside Mr Phillips' evidence that when he went to switch on the PLC on 15 December 2010, he discovered that the Aurora PI in the media room in the laboratory was activated and flashing red and a set of scales was damaged, and leaving aside the inference to be drawn from the fact that previous events had damaged some but not all of the household electrical equipment, the respondent's evidence merely combatted as opposed to defeating, the evidence of Messrs Page and Piper, (which was based on the work of Francois Martzloff as to the vagaries of surge occurrences), that because of the nature of a transient surge, while there may be minimal attenuation, not all equipment will be damaged all the time, and it is impossible to predict which equipment will be damaged.
10. As to the appellant's ground of appeal that the learned trial judge erred in preferring the evidence of the respondent's experts over that of the appellant's, without analysis of the reasoning underpinning their respective opinions of the expert witnesses, I accept that his Honour did not advance reasons for preferring the respondent's experts, beyond reference to their experience, and that he failed to note that Mr Piper was an electronics engineer who might be thought to better understand the dynamics of the PLC. That Mr Gillespie was preferred by his Honour over Messrs Page or Piper, because of Mr Gillespie's "particular qualifications and experience in electricity transmission, and the design and maintenance of PLCs in the electricity transmission business", and that his evidence was "confirmed by ... and consistent with the modelling evidence before the Court", is to my mind difficult to justify given the exchanges between the witnesses in the "joint evidence" of the experts, and in view of my reservations about the Manitoba Modelling. I have a similar view as to his Honour's preference for the evidence of Dr D'Alessandro over that of Nicholas Johnston, "based upon the former's qualifications, experience and publication of learned articles", given that Dr D'Alessandro's evidence also relied on Dr Muthumuni's modelling and that as noted, on one set of assumptions made by Dr D'Alessandro his conclusion was that voltage sufficient to damage the PLC was indeed produced.
11. To my mind, however, the case, being a circumstantial case, it was not to be decided solely by choosing between these experts. As I have observed, the respondent's expert evidence admitted some if not all, of the possibilities that the appellant hypothesised. As Porter J observed in Langmaid (above), at [139], that can be enough, depending on other evidence. The appellant did not have to exclude every hypothesis consistent with an absence of negligence on the part of the respondent.
12. However, even if it was appropriate or desirable to attempt to decide the case by choosing between the experts on either side, the non-expert circumstantial evidence operated in two ways:
    1. it combined with the appellant's expert evidence, and the existence of the possibility of a causal connection left open on the respondent's expert evidence, to symbiotically point to causation-in-fact on the balance of probabilities as asserted by the appellant, and
    2. it also underpinned comfortable satisfaction of a causal connection by militating against acceptance of Mr Gillespie's speculation in his experts memorandum of 12 March 2018 as to ten possible non-negligent causes of the respondent's damage, and at the same time facilitating acceptance of the appellant's expert evidence by sitting conformably with it.

1. The non-expert evidence, taken together with the appellant's expert evidence, not shown empirically to be fallacious, and taken together with the admitted possibility of the appellant's hypotheses and the lack of a reasoned and related alternate cause of the appellant's damage, to my mind combine to produce an irresistible circumstantial case.
2. In saying this, I should allow that, contrary to my view, it may not be universally accepted that a fair reading of the respondent's expert evidence, admitted of the possibility of every one of what I have characterised as the appellant's three hypotheses as to factual causation. However, I think it undeniable that such was the case with the two flashover hypotheses.
3. Although it bore no legal burden of proof, the respondent's expert evidence did not establish that a high voltage surge event could not have been responsible for the damage to the PLC or that it was empirically less likely than a competing hypothesis. The modelling relied upon to establish that sufficient voltage would not have been generated to cause the damage is far from empirical evidence, and the theories that the fuses would have blown if there was sufficient voltage, or that other equipment would also have been damaged, are adequately met by the contrary views of the appellant's experts and supported by the strong non-expert circumstantial evidence of years of problems which effectively disappeared after the equipment on the pole was re-configured in 2012. As Porter J said in Langmaid (above) at [141]:

"As to causation, the law does not insist on the need to demonstrate the mechanism of loss or damage 'to a fine degree': Duma v Mader International Pty Ltd [2013] VSCA 23 per Neave JA at [3]. See also Strong v Woolworths Ltd (above) at 196, [34], and Kuhl v Zurich Financial Services Australia Pty Ltd [2011] HCA 11; (2011) 243 CLR 361 per French CJ and Gummow J at 381 - 382 [53] - [54]."

1. At a relatively high level of abstraction, the learned trial judge erred by rejecting the non-expert circumstantial evidence as inadmissible or of no value, and in failing to have regard to that evidence, both as to its importance to the appellant's circumstantial case and as facilitating acceptance of the appellant's expert evidence and militating against acceptance of the respondent's expert evidence. A review of the 815 page transcript of the trial and of the exhibits tendered on either side, reveals those errors to my satisfaction at a micro level.
2. It is well understood that where evidence is circumstantial, an inference can be drawn from a combination of facts, none of which when viewed alone would support that inference (Fennell v The Queen (above), at [82]; Hillier (above) at 638 [48]; Chamberlain v The Queen [No 2] (above at 536) per Gibbs CJ and Mason J and semble Brennan J and Shepherd v The Queen [1990] HCA 56; (1990) 170 CLR 573 at 579). As Lord Cairns, with whom Lord Hatherley agreed, said in Bellhaven v Stenton Peerage (above) at 279:

"My Lords, in dealing with circumstantial evidence, we have to consider the weight which is to be given to the united force of all the circumstances put together. You may have a ray of light so feeble that by itself it will do little to elucidate a dark corner. But on the other hand, you may have a number of rays, each of them insufficient, but all converging and brought to bear upon the same point, and, when united, producing a body of illumination which will clear away the darkness which you are endeavouring to dispel."

With respect, it seems to me that the learned trial judge did not approach the case in that way.

1. The "key circumstances" in the case asserted by the appellant are set out by its counsel Mr Read SC and Mr Cox, in their written submissions. They are all listed, however to my mind, the significant and largely uncontroversial "rays of light" are those adumbrated to the following effect:
   • The Potting Machine was switched off by the Plaintiff (through its directors, or one of them) on 9 December 2010 .
   • On 10 December 2010 the Defendant's recloser C690306 on Glengarry Road, which supplied 22kV electricity to the Pole, tripped four times and locked out at 23:38 hours.
   • Operation of the recloser will cause a voltage surge.
   • On 16 December 2010, the Plaintiff (through its Directors, or one of them), turned the Potting Machine on. The Potting Machine did not operate when turned on .
   • The damage to the PLC was consistent with being caused by a voltage surge.
   • Over 20 years of harm occurred to electrical equipment powered by electricity supplied from the pole.
   • Harm was occurring to equipment on different circuits and in different areas of the property indicating a cause common to all: the electrical supply.
   • Of that harm on at least six separate occasions there was evidence available to show that the HV protective device (recloser) had operated at a time just prior to that damage.
   • In January 2012 conduit was placed on the LV conductor to stop further flashovers until the Pole could be fixed.
   • After the conduit was fitted Brocklands suffered no further electrical harm.
   • Aurora replaced the high voltage and low voltage earthing systems at the base of the Pole (20 January 2012).
   • Aurora lifted the HV bushings so as to adequately separate the HV and LV conductors. This was done by raising the height of the Transformer on the Pole (27 June 2012).
   • The equipment at Brocklands suffered no further demonstrably electrically caused harm.
2. Taken together, either with or without the appellant's contested expert evidence, but viewed through the lens of the respondent's experts acceptance of the possibilities of a causal link, and the absence of other demonstrated and reasonably possible sources of voltage surge or reasoned cause of the damage to the PLC, those "rays of light" amply justify, in my view, the drawing of an inference as to causation in favour of the appellant.
3. The respondent in its written submissions contended that;

"The evidence was that some of the items that failed were inspected or repaired by, or sent for repair to, third parties: T133-134, T255, T277-278. None of those third parties gave evidence, nor were any associated documents tendered. The LG TV was replaced under warranty: T134. The associated paperwork was not tendered. There were replacements: the circuit boards on the Southcorp gas heater were replaced on at least two occasions (T112) and the Richdel irrigation solenoid controllers were replaced several times (T276). No evidence was tendered in relation to the basis on which each was replaced, by the replacing party or by anyone else electrically qualified to diagnose the reason replacement was required."

1. That submission however, and the respondent's oral submissions made at yesterday's hearing, ignore the fact that in January 2012 conduit was placed on the LV conductor to stop further flashovers until the pole could be further modified, and that, after the conduit was fitted, the appellant suffered no further electrical caused equipment damage. And it ignores the fact that on 20 January 2012 the high voltage and low voltage earthing systems at the base of the pole were replaced, and on 27 June 2012 the HV bushings were lifted, so as to adequately separate the HV and LV conductor, by raising the height of the transformer on the pole. Again, after those things were done the appellant suffered no further apparent electrical harm.
2. The respondent also submits that other possible causes of the appellant's harm included interference or interaction between different equipment onsite, harmonics, "unbalance loading of phases", incorrect rating of equipment, sensitivity of equipment to voltage fluctuations, poor quality equipment, poor insulation, workmanship and the ten common causes for computer-related equipment to fail, mentioned in Mr Gillespie's report of 1 August 2017 (Exhibit D75) and his expert memorandum. In addition, the respondent contends that the converter onsite which converted single phase power to three phase power could produce voltages outside the normal range, and that starting large motors can cause voltage drop on the supply to other equipment.
3. As was observed in Langmaid (above), it is possible to acknowledge the combined strength of the possibilities raised by a defendant while at the same time finding that it is more probable than not that one or more of the alleged breaches caused the asserted damage. However possible causes advanced on behalf of the respondent were highly speculative. Moreover, it must be observed that the evidence demonstrated that the electrical wiring at the property was tested and found to be substantially in accordance with AS3000, the PC was tested and found to be wired correctly so as to produce the correct voltage to the PLC, and there was no evidence of large motors present on the property in 2010. Further there was no evidence to suggest what equipment may have been present that might have interacted to cause a voltage surge.
4. Ultimately, it follows, from all that I have said, that I regard the errors I earlier, respectfully, alluded to on the part of the learned trial judge, but of which I deferred consideration, as operative errors, which are dispositive of the appeal.
5. In my view, ground 2 of the notice of appeal is made out as are the grounds that the learned trial judge:

"5 Erred at [201] in finding that the evidence of a flashover event was 'mere conjecture' ...

1. Erred in finding at [259] that there was not a high voltage surge event that damaged the PLC ...
2. Erred in failing to find that the agreed distance of separation of the high and low voltage conductors could give rise to a flashover event.
3. Erred at [124] in disregarding the evidence of Mr Richardson.
4. Erred at [131] in attributing the evidence of Mr Whiddon no weight ...
5. At [155] the learned trial judge erred in concluding that the evidence of Ms Brock, Hetherington and Mr Phillips was inadmissible opinion pursuant to s 76 of the Evidence Act 2001 ...
6. Erred in respect of the evidence of Dr Muthumuni:

(c) At [248] in disregarding the absence of a proper basis for his opinion because the plaintiff did not put the shortcomings listed at [243 and 244] to Dr Muthumuni."

1. I do not find it necessary to consider the ground that his Honour erred at [39] of his reasons in "finding" that the cost of rectifying 50,000 transformers would be "onerous to the point of being unreasonable" in circumstances where there was not any evidence before the Court of the costs of rectification or that it was needed. That observation by his Honour was not to my mind critical to his reasoning to the conclusion at [43], that AS2067:1984 was the only standard applicable to the respondent's installation. I find no error in that reasoning notwithstanding the appellant's asserted "maintenance failure" case. Given the nature of the shortcomings with the installation and considering what was involved in modifying the pole, the burden of taking precautions to avoid similar risks of harm is not an issue in this case in my view.
2. As a provider of infrastructure along which a supplier of electricity, delivers electricity to consumers, it cannot be doubted, in my view, that the respondent owed a duty of care to the appellant to take reasonable care to avoid foreseeable damage to the appellant and its property. Given the inherently dangerous nature of electricity, the standard of that duty of care was high. However in my opinion it remained the standard of care which was reasonable in the circumstances and was not so onerous as to "amount practically to a guarantee of safety" as was submitted by the appellant in reliance on the statement in Burnie Port Authority v General Jones Pty Ltd [1994] HCA 13; (1994) 179 CLR 520 at [41]. In any event, such a standard was not pleaded against the respondent, nor contended for at trial and it ought not in such circumstances be entertained on this appeal.
3. In my view, the whole of the evidence compels the drawing of the inference that a breach of the respondent's pleaded duty of care caused the relevant harm. At the very least the evidence supports the conclusion that at the time the PLC was damaged, the supply of electricity exceeded the permissible maximum of 345 volts for a "length of time", as the PLC could withstand 500 volts for one minute and yet it was damaged. Also, at the very least, there was inadequate separation of the HV and LV conductors - so much was admitted by the respondent in its defence. So too was the fact of a misalignment of an arc gap rod admitted in the defence. And, while s 12 of the Civil Liability Act prevents the subsequent taking of action, that would have avoided the risk, from constituting "evidence of liability", the circumstance that modifications to the pole resulted in an end to the historic problems with the appellant's electrical equipment is one that is influential in fact finding as to breach of duty.
4. I conclude, as did Mr Piper, that the most likely cause of damage to the PLC was a surge of high voltage electricity which bypassed the surge protection on the transformer and arced to the active 'a' conductor where it travelled to and damaged the PLC unit by one or more unknown paths "that cannot be empirically determined". I do not consider that such a conclusion is mere speculation, or a matter of choosing between guesses. Whichever of the three possible mechanisms, or whichever combination of them, caused the surge, I am satisfied that it was as result of a breach of the respondent's duty to take reasonable care to avoid foreseeable harm to the appellant. The respondent, or more correctly, the entity for whom the respondent subsequently assumed legal liability, well knew of the problems said to have emanated from the pole historically and it had been inspected many times over many years.
5. In reaching my conclusion I have not found it necessary to call in aid the approach discussed in Betts v Whittingslowe [1945] HCA 31; (1945) 71 CLR 637 and explained in Roads and Traffic Authority v Royal [2008] HCA 19, 82 ALJR 870 by Kirby J at 888 [88] and Amaca Pty Ltd v Booth [2011] HCA 53, 246 CLR 36 at 57 [49]. That approach is, after all, only "an aspect of an available process of drawing of conclusions about causation": Bauldserstone Hornibrook Engineering Pty Ltd v Gordian Runoff Ltd [2008] NSWCA 243, 5 ANZ Insurance Cases 61-780 per Allsop P (Beazley and Campbell JJA agreeing) at [240]. I find that in this case, an ex post facto inference of causation-in-fact is justified.
6. I am affirmatively persuaded that the respondent's breach of duty was a necessary causal element of the occurrence of the appellant's particular harm, namely the damage to the PLC. In my view it goes without saying that in the case of as a provider of network infrastructure along which a supplier of electricity delivers electricity to consumers, it is appropriate that the scope of the respondent's liability, should extend to that harm.
7. I can find no error in the reasoning of the learned trial judge in concluding that the case was not one of pure economic loss, but one of economic loss consequent on property damage. The fact that there may be no particularised claim for the cost of the PLC does not alter that.
8. Finally, the respondent submits that the pleadings and the evidence do not allow the appellant to establish a duty at all, and particularly one that would extend to an obligation to guard against the risk of consequential economic loss. It is submitted by the respondent that the operation of s 13(1)(b) of the Civil Liability Act deprives the appellant of the right to judgment for damages to be assessed. I do not accept those submissions. The prerequisite to a finding that breach caused "particular harm" as set out in s 13(1)(b), namely, that it is appropriate for the scope of the liability of the person in breach to extend to the harm so caused, does not require a Court, once "harm" is established, to assess the amount of "loss" or "damage" before it can make a finding as to the scope of a defendant's liability for that harm. In Hunt & Hunt Lawyers v Mitchell Morgan Nominees Pty Ltd [2013] HCA 10, 247 CLR 613 at [24], French CJ and Hayne and Kiefel JJ said, in a case involving the Civil Liability Act 2002 (NSW):

"In the identification of the damage or loss that is the subject of the claim, it is necessary to bear in mind that damage is not to be equated with what is ultimately awarded by the court, which is to say the 'damages' which are claimed by way of compensation and which are assessed and awarded for each aspect of the damage suffered by a plaintiff. Damage, properly understood, is the injury and other foreseeable consequences suffered by a plaintiff."

1. The appeal should succeed and there should be judgment for the appellant for damages to be assessed. The action should be remitted to a judge or the associate judge for the assessment of damages.

BROCKLANDS PTY LTD v TASMANIAN NETWORKS PTY LTD

1. I agree with Blow CJ and Estcourt J that the appeal should be allowed and that judgment should be entered for the appellant against the respondent for damages to be assessed by a judicial officer other than the learned trial judge. I agree with the reasons of Blow CJ.

[1] [1984] HCA 7; (1984) 153 CLR 521 at 535.

[2] (1980) 71 Cr App R 228 at 231.

[3] (1875) 1 App Cas 278 at 279.

[4] (1973) 4 SASR 353 at 373.

[5] [1972] NZLR 34 at 37‑38, 40.

[6] [1963] HCA 44; (1963) 110 CLR 234 at 242.