Negligence - Breach of statutory duty - Duty owed by owner of mine site to employee of contractor - Absence of system or instruction to clean signs - Turns on own facts

Civil Liability Act 2002

Elphick v Westfield Shopping Centre Management Co Pty Ltd [2011] NSWCA 356

Hamilton v Nuroof (WA) Pty Ltd [1956] HCA 42; (1956) 96 CLR 18

Kuhl v Zurich Financial Services Australia Ltd [2011] HCA 11

Laing O'Rourke (BMC)Pty Ltd v Kirwin [2011] WASCA 117

Leighton Contractors Pty Ltd v Fox [2009] HCA 35

Podrebersek v Australian Iron & Steel Pty Ltd [1985] HCA 34; (1985) 59 ALJR 492

Stevens v Brodribb Sawmilling Co Pty Ltd [1986] HCA 1; (1986) 160 CLR 16

1 The defendant is the owner of the Mount Whaleback iron ore mine. The provisions of the Mines Safety and Inspection Act 1994 (the Act) apply to the defendant's Mount Whaleback mine site.

2 From 2003 to 2007 the defendant engaged MacMahon Contractors Pty Ltd (MacMahon) to carry out the mining activities at the mine site. The terms of their agreement and their respective responsibilities were contained in the contract executed by the parties marked BHP-03-062 (the mine operation contract) and tendered by consent at trial (exhibit E).

3 At all material times the plaintiff was employed by MacMahon as a truck driver at the Mount Whaleback mine site.

4 Part of the works required to be performed by MacMahon included the construction and maintenance of the haul roads upon which the trucks were to travel to carry out the mining operations. At the junction of the main haul road and a side road going to a waste dump was the intersection of the known 'W19'. At this point two traffic islands approximately 6 m long, 3 m wide and 1.5 m high were created to form the intersection and separate the vehicles.

5 The islands were constructed using windrows of waste soil with two Haulpak tyres being positioned, one on top of the other, at the ends of each island. Waste soil was then loaded into the centre of the tyres to secure them in position. A jarrah stake was driven into the soil in each stack of tyres and a 2 inch pipe to which 'Keep Left' signs were secured was placed over the top of the stake and hammered into soil until firmly secured in place. Each stack of tyres at the end of each windrow was approximately 1.5 m (5 feet) high and 3 m (9 feet) wide.

6 It is the plaintiff's case that on 6 December 2005, whilst standing on one of the tyre stacks at the W19 intersection to clean the road signs, he fell to the ground and suffered an injury to his right leg (the incident). The plaintiff attributed his fall to the soft fine powdery uncompacted soil described as 'bulldust' used in the tyres.

7 The plaintiff was initially compensated in respect of the injury suffered by MacMahon and its statutory workers' compensation insurer. As the plaintiff was unable to satisfy the statutory threshold he is precluded from pursuing any claim against MacMahon outside of the Workers' Compensation and Rehabilitation Act 1981.

8 In June 2008 the plaintiff's statutory workers' compensation entitlements were exhausted.

9 In August 2008 the plaintiff commenced proceedings against the defendant as the owner of the Mount Whaleback mine site - alleging breaches of a duty owed to him under the Act and at common law.

10 Omitting the formal parts, the plaintiff pleads his claim against the defendant as follows:

1. At all material times, MacMahon had a contract with the Defendant to cart high grade ore and waste at the mine site.
2. At all material times the Defendant was:

5.1 in control and occupation of the mine site and/or;

5.2 carried on mining operations within the meaning of Section 4 of the Mines Safety & Inspection Act 1994 at the mine site;

5.3 responsible for traffic and safety management of the roads at the mine site.

6A There was a sufficient relationship of proximity between the Plaintiff as truck driver for MacMahon at the mine site and the Defendant as occupier of the mine site and or the Defendant being in control of traffic and safety management of the roads at the mine site for the Defendant to owe the Plaintiff a duty of care at common law.

6.1 to take all reasonable care for the Plaintiff's safety whilst he was on the mine site;

6.2 to take all reasonable care not to expose the Plaintiff to the risk of foreseeable injury whilst he was on the mine site;

6.3 to take all reasonable steps to provide a safe mine site;

6.4 to take reasonable care to ensure that the Plaintiff did not suffer injury as a result of danger due to the state of the premises.

6B Further or alternatively pursuant to Section 13 of the Mines Safety & Inspection Act 1994, the Defendant as principal employer of the mine site, owed the Plaintiff a duty to take such measures as were practicable to ensure that the mine site and the means of access to and egress from the mine site was such that the Plaintiff were not exposed to hazards.

6C Further or alternatively pursuant to Section 15A of the Mines Safety & Inspection Act 1994, the Defendant as the principal employer owed a duty to the Plaintiff as if the Defendant were the employer of the Plaintiff to:

(a) provide and maintain a workplace, plant and system of work of a kind that so far as was practicable, did not expose the Plaintiff to hazards;

(b) provide such information, instructions and training to and supervision of the Plaintiff as was necessary to enable him to perform his work in such a manner that he was not exposed to hazards;

(c) consult and cooperate with safety and health representatives and other employees at the mine site regarding operational safety and health at the mine site.

1. On 6 December 2005 at or about 7.30am, the Plaintiff was required to clean road signs at the intersection on W19 at the Defendant's mine site whilst employed by MacMahon. The task of cleaning consisted of washing dust and soil from signs that were secured inside two Haulpak tyres on tracks at the mine site. The task involved the Plaintiff using a bucket of water and a rag and parking his vehicle in a safe location and then climbing onto the Haulpak tyres so as to wipe the sign with the rag. There were four signs located in the centre of the main haul road, two on either side of the intersection with W19. Between each of the two signs on either side, there was a wind row of soil approximately 5 feet high. The poles of the signs were buried in soil inside two Haulpak tyres which were stacked on top of each other. Each Haulpak tyre was approximately 2.5 feet high and 9 feet wide. The two Haulpak tyres were filled with soil to hold the sign in place. The Plaintiff was required to step onto the tyres onto the soil in order to access the sign and clean the sign with the rag. The Plaintiff cleaned three signs in this manner and the soil inside the first three tyres had been compact and firm and the Plaintiff was able to stand inside the soil in the first three signs without incident. The Plaintiff then proceeded to clean the fourth sign and placed his right leg onto the soil inside the two Haulpak tyres and unbeknown to the Plaintiff, the soil was not compact or solid and did not support the Plaintiff's weight, resulting in the Plaintiff's right leg sinking into the soil and the Plaintiff lost balance and fell from a height of about 5 feet onto the ground below ('the accident').

8A The accident was caused by the breach of the duty of care referred to in paragraph 6A above by the Defendant, its servants or agents.

PARTICULARS OF NEGLIGENCE

8.1 Failed to warn the Plaintiff of the risk of injury arising from climbing onto or into the tyres to access and clean the sign;

8.2 Failed to supply the Plaintiff with a long handled broom with a scraper similar to those used to clean windscreens in garages to clean the signs instead of climbing onto or into the tyres;

8.3 Failed to employ or design a system of cleaning of the signs by instructing or requiring the Plaintiff to use long shanked brooms to avoid the necessity to step on or into the tyres to obtain the required height to clean the signs;

8.4 Failed to ensure that the soil inside the Haulpak tyres was solid and compacted;

8.5 Failed to inspect the condition of the soil inside the Haulpak tyres so as to determine whether or not it was a safe working platform to stand on.

8B Further or alternatively the accident was caused by the breach of the duty of care specified in paragraph 6B above.

PARTICULARS OF BREACH OF SECTION 13

OF THE MINES SAFETY & INSPECTION ACT 1994

(a) failed to warn the Plaintiff of the risk of injury arising from climbing onto or into the tyres to access and clean the sign;

(b) failed to supply the Plaintiff with a long handled broom with a scraper similar to those used to clean windscreens and garages to clean the signs instead of climbing onto or into the tyres;

(c) failed to employ or design a system of cleaning of the signs by instructing or requiring the Plaintiff to use long shanked brooms to avoid the necessity to step on or into the tyres to obtain the required height to clean the signs;

(d) failed to ensure that the soil inside the Haulpak tyres was solid and compacted;

(e) failed to inspect the condition of the soil inside the Haulpak tyres so as to determine whether or not it was a safe working platform to stand on.

8C Further or alternatively the accident was caused by the breach of the duty of care referred to in paragraph 6C above.

PARTICULARS OF BREACH OF SECTION 15A

OF THE MINES SAFETY AND INSPECTION ACT 1994

(a) Failed to provide and maintain a safe workplace, plant and system of work so as to avoid exposing the Plaintiff to hazards and the Plaintiff will rely on paragraphs 8.1 to 8.5 above as particulars of the breach;

(b) Failed to provide such information, instructions to enable him to perform his work in such a manner that he was not exposed to hazards and the Plaintiff will rely on paragraphs 8.1 to 8.5 above as particulars of the breach;

(c) Failed to consult and cooperate with safety and health representatives at the mine site regarding occupational safety and health at the mine and the Plaintiff will rely on paragraphs 8.1 to 8.5 above as particulars of the breach.

1. As a result of the accident, the Plaintiff suffered injuries.

(b) does not admit that it carried on mining operations within the meaning of the Act, or that it was in control of the mine site and responsible for traffic and safety, maintenance (par 3 of the Defence);

(c) denies that it owed the plaintiff the duty alleged;

(d) puts the plaintiff to proof of the circumstances of the incident and the injury suffered by him;

(e) pleads specifically an 'independent contractor' defence - that is to say, that if the plaintiff suffered the injury, such loss was caused by the negligence of the plaintiffs actual employer (MacMahon) who was an independent contractor. The defendant says it used all reasonable care and skill and care in selecting and supervising MacMahon and that in the circumstances is not liable to the plaintiff (pars 11 - 14);

(f) alleges that the plaintiff was guilty of contributory negligence (par 15);

(g) pleads by way of special defence, that the risk arising from climbing onto the Haulpak tyres to clean the signs was an 'obvious risk' as defined in s 5F of the Civil Liability Act 2002 (CLA). Accordingly the plaintiff is presumed to have known the risk such that the defendant was under no duty to warn him of such an obvious risk (pars 16 - 17);

(h) says that the plaintiff's injury and loss was caused or contributed to by the plaintiff's pre-existing unrelated medical conditions (par 18).

12 By his reply, filed pursuant to leave granted at the completion of evidence on 12 August 2011, the plaintiff relies on s.15A (5) of the Act in response to the defendants 'independent contractor' defence.

13 Pursuant to s. 15A(2) of the Act, s. 9 of the Act has effect as if the defendant was the employer of MacMahon and any employee of MacMahon in relation to matters over which it had the capacity to control.

14 The duty imposed on an employer by s. 9 of the Act was, so far as it is practicable, to provide and maintain a safe working environment, including the provision and maintenance of the workplace, plant and systems of work, such that the employees are not exposed to hazards.

15 Section 15A(5) of the Act provides for the purpose of that section, an agreement or arrangement is void if it purports to give control to a contractor or any person employed by the contractor of any matter that comes within s 9 and it is a matter over which the principal has the capacity to exercise control.

16 The plaintiff contends that the defendant, as the owner of the mine who engaged MacMahon to undertake the mining operations on the mine site, yet retained control of the work to be undertaken by MacMahon, is within the definition of 'principal employer' within the meaning of s 4 of the Act.

17 It follows that if the plaintiff is correct in the characterisation of the relationship between the defendant and MacMahon, the defendant's plea that the plaintiff's injury was caused by the negligence of an independent contractor for whose negligence the defendant is not liable, is not open to the defendant by way of defence. The defendant cannot simply point to MacMahon and assert its careful selection of the plaintiff's employer, MacMahon, in answer to the plaintiff's claim under s 15A of the Act. Pursuant to the Act, the defendant remains liable as if it was the principal employer of the plaintiff.

18 The issues for determination on the pleading are:

(a) whether the defendant owes the plaintiff a duty of care at common law and/or pursuant to the Act. This issue will require consideration of, inter alia, the defendant's activities on the mine site and the extent to which it remains in control and occupation of the site;

(b) the nature of the duty owed to the plaintiff, if any, and what response was required of the defendant in discharge of that duty;

(c) the circumstances of the incident, including whether the plaintiff's injury occurred as a consequence of any breach of duty on the part of the defendant;

(d) whether the risk of injury to the plaintiff was an 'obvious risk' within the meaning of such term in the CLA such that no warning was necessary;

(e) whether the plaintiff was guilty of contributory negligence;

(f) whether the plaintiff suffered the injury alleged; and if so;

(g) what is the measure of loss and damages suffered by the plaintiff.

19 The plaintiff says that the defendant was the entrepreneur who sought to benefit from the conduct of mining operations whilst retaining the capacity to control MacMahon on the mine site. Accordingly it owed a common law duty to exercise reasonable care for the safety of persons who it knew were likely to attend the mine: Stevens v Brodribb Sawmilling Co Pty Ltd [1986] HCA 1; (1986) 160 CLR 16.

20 In Elphick v Westfield Shopping Centre Management Co Pty Ltd [2011] NSWCA 356 Whealy JA (Young JA and Sackville AJA agreeing) [60] - [61] summarised the relevant principles.

There have been many cases, especially in recent times, where an employee injured in a workplace or industrial situation, has sought to include within the ambit of liability persons and corporations beyond his immediate employer. This is understandable in the light of contemporary legislation, part of the cycle of tort reform, which has sought to restrict significantly the damages payable by an employer to his worker. Moreover, especially in the building industry, the immediate employer may turn out to be a 'man of straw'. For that reason, also, the injured worker often looks to find and impose liability upon a more substantial defendant.

Against this background, decided cases have shown at times an uncertainty of approach. This uncertainty has, in a number of respects, been resolved by recent decisions of the High Court of Australia. The primary judge referred to several of these in his reasons for decision. However, it may be convenient to summarise in very brief form the principles I see as being relevant to the resolution of the issues here. This is not intended to be an exhaustive summary, or, for that matter, a comprehensive analysis. The relevant principles in the present matter are, as I see them, as follows:

(a) The duty of care owed by Westfield to Mr Elphick was that of an occupier. This duty was succinctly stated in Australian Safeways Stores Pty Ltd v Zaluzna (1987) 162 CLR 479 at 488:

... the fact that [injured person] was a lawful entrant upon the land of the [occupier] establishes a relationship between them which of itself suffices to give rise to a duty on the part of the [occupier] to take reasonable care to avoid a foreseeable risk of injury to the [injured party].

(b) This duty, in circumstances where the occupier engages an independent contractor to carry out aspects of its enterprise, does not give rise to a duty of care towards an employee of the independent contractor akin to the duty of an employer to his employee (see Leighton Contractors v Fox at [48]:

The relationship between principal and independent contractor is not one which, of itself, gives rise to a common law duty of care, much less to the special duty resting on employers to ensure that care is taken.)

(c) In certain circumstances, the duty to take reasonable care will, however, extend to responsibilities involved in the system of work utilised by the independent contractor. Whether this is so or not will depend on a fact-intensive investigation to determine whether there is the necessary interdependence of the activities carried out in the enterprise under consideration. As Mason J said in Brodribb at 31:

The interdependence of the activities carried out in the forest, the need for co-ordination by Brodribb of those activities and the distinct risk of personal injury to those engaged in the operations, called for the prescription and provision of a safe system by Brodribb. Omission to prescribe and provide such a system would expose the workers to an obvious risk of injury. Although the obligation to provide a safe system of work has been regarded as one attaching to an employer, there is no reason why it should be so confined. If an entrepreneur engages independent contractors to do work which might as readily be done by employees in circumstances where there is a risk to them of injury arising from the nature of the work and where there is a need for him to give directions as to when and where the work is to be done and to co-ordinate the various activities, he has an obligation to prescribe a safe system of work. The fact that they are not employees, or that he does not retain a right to control them in the manner in which they carry out their work, should not affect the existence of an obligation to prescribe a safe system. Brodribb's ability to prescribe such a system was not affected by its inability to direct the contractors as to how they should operate their machines.

(d) Where, however, the occupier has engaged the services of an independent contractor whose task it is to control its employee's systems of work without supervision by the occupier, there may, depending once again on a fact-sensitive enquiry, be no liability imposed on the occupier for a failure by the independent contractor to control its own system of work. As Brennan J said in Brodribb at 47 - 48:

The circumstances may make it necessary for the entrepreneur to retain and exercise a supervisory power or to prescribe the respective areas of responsibility of independent contractors if confusion about those areas involves a risk of injury. But once the activity has been organized and its operation is in the hands of independent contractors, liability for negligence by them within the area of their responsibility is not borne vicariously by the entrepreneur. If there is no failure to take reasonable care in the employment of independent contractors competent to control their own systems of work, or in not retaining a supervisory power or in leaving undefined the contractors' respective areas of responsibility, the entrepreneur is not liable for damage caused merely by a negligent failure of an independent contractor to adopt or follow a safe system of work either within his area of responsibility or in an area of shared responsibility.

21 The plaintiff further maintains his claim against the defendant on the basis that the defendant is within the definition of a 'principal employer' within the meaning ascribed in s 4 of the Act and accordingly owes a duty of care to the plaintiff pursuant to s 13 and s 15A of the Act.

22 Pursuant to s4 of the Act, 'principal employer':

(a) in relation to a mine (other than a mine where only exploration operations are being carried out), means the employer who is the proprietor, lessee, or occupier of the mine and who has overall control and supervision of the mine, mining operations at the mine and the manager of the mine; and

(b) in relation to a mine where only exploration operations are being carried out, means the employer who has overall control and supervision of the exploration operations at the mine and the exploration manager appointed for those operations;

23 Section 13 of the Act is in the following terms:

1. Principal employers and managers, duties of

The principal employer at and the manager of a mine must take such measures as are practicable to ensure that the mine and the means of access to and egress from the mine are such that persons who are at the mine, or use the means of access to or egress from the mine, are not exposed to hazards.

24 The plaintiff says that pursuant to s 13 of the Act the defendant owes a duty of care akin to that of an occupier to ensure that persons on the mine site such as the plaintiff are not exposed to hazards.

25 Section 15A of the Act is in the following terms:

(1) This section applies where a person (the principal) in the course of mining operations engages a contractor (the contractor) to carry out work for the principal.

(2) Where this section applies, sections 9 and 9A have effect -

(ii) any person employed or engaged by the contractor to carry out or assist in carrying out the work concerned,

in relation to matters over which the principal has the capacity to exercise control; and

were employees of the principal in relation to matters over which the principal has the capacity to exercise control.

(5) An agreement or arrangement is void for the purposes of this section if it purports to give control to -

(d) is a matter over which the principal has the capacity to exercise control,

but this subsection does not prevent the making of a written agreement as mentioned in section 15D(3).

26 Pursuant to s 9 of the Act an employer has a duty to persons working on the site. So far as it is practicable, an employer must provide and maintain a safe working environment including, inter alia, providing and maintaining workplaces, plant and systems of work whereby the employees are not exposed to hazards. A 'hazard' is 'anything that may result in injury to the person or harm to the health of the person' (s 4 of the Act).

27 It is the plaintiff's case that the defendant owes a duty of care to the plaintiff as if it was the plaintiff's employer.

28 In Laing O'Rourke (BMC)Pty Ltd v Kirwin [2011] WASCA 117 the Court of Appeal considered the extent of the duty owed by a defendant pursuant to s 19(1) of the Occupational Safety and Health Act 1984 - the terms of which (including the relevant definitions) mirror s 9 of the Act.

29 At [30] - [36] Murphy AJ, with Martin CJ and Mazza J concurring, expressed the duty owed by the owner of a mine site to those deemed to be its employees and the appropriate response, in the following terms:

The duty imposed on an employer by s 19(1) is not an absolute duty: Chugg v Pacific Dunlop Ltd [1990] HCA 41; (1990) 170 CLR 249, 251 (Brennan J); Interstruct Pty Ltd v Wakelam (1990) 3 WAR 100, 108, 109 (Wallace J, Rowland J agreeing); Wylie v South Metropolitan College of TAFE [2003] WASCA 34 [45]; Tobiassen v Reilly [2009] WASCA 26; (2009) 178 IR 213 [59]. Important in this regard is the phrase 'so far as is practicable', which qualifies the duty in s 19(1). The words 'practicable' and 'risk' are defined in s 3(1) as follows:

practicable means reasonably practicable having regard, where the context permits, to -

(a) the severity of any potential injury or harm to health that may be involved, and the degree of risk of it occurring; and

(i) the injury or harm to health referred to in paragraph (a); and

(ii) the risk of that injury or harm to health occurring; and

(iii) means of removing or mitigating the risk or mitigating the potential injury or harm to health; and

(c) the availability, suitability, and cost of the means referred to in paragraph (b)(iii);

risk, in relation to any injury or harm, means the probability of that injury or harm occurring;

It follows from the definition of 'practicable' that the obligation imposed on an employer by s 19(1) is an obligation to provide and maintain a working environment in which its employees are not exposed to hazards only so far as is reasonably practicable. The words 'reasonably practicable' are ordinary words, bearing their ordinary meaning and simply call for the making of a value judgment in light of all the facts: Slivak v Lurgi (Australia) Pty Ltd [2001] HCA 6; (2001) 205 CLR 304, 322 (Gaudron J). Hindsight may mislead. As Harper J said in Holmes v RE Spence & Co Pty Ltd (1992) 5 VIR 119, 123 - 124, in relation to the equivalent provision in the Victorian legislation:

The Act does not require employers to ensure that accidents never happen. It requires them to take such steps as are practicable to provide and maintain a safe working environment. The courts will best assist the attainment of this end by looking at the facts of each case as practical people would look at them: not with the benefit of hindsight, nor with the wisdom of Solomon, but nevertheless remembering that one of the chief responsibilities of all employers is the safety of those who work for them.

That approach has been adopted in Western Australia: see MacCarron v Future Engineering & Communication Pty Ltd (Unreported, WASC, Library No 980350, 23 June 1998) 11; Shepherd v Co-Operative Bulk Handling Ltd [2001] WASCA 413 [55].

The 'state of knowledge' relating to, inter alia, the injury, the risk of injury and the means of removing or mitigating the risk, referred to in the definition of 'practicable', is objective. It is that possessed by persons generally who are engaged in the relevant field of activity and not merely the actual knowledge in fact possessed by a specific employer in the particular circumstances: Hamersley Iron Pty Ltd v Robertson (Unreported, WASC, Library No 980573, 2 October 1998) 22; Wylie v South Metropolitan [45]; Silent Vector Pty Ltd v Shepherd [2003] WASCA 315 [12] (although that case concerned s 22 of the Act, the same consideration applies to s 19); Reilly v Devcon Australia Pty Ltd [2008] WASCA 84; (2008) 36 WAR 492 [60].

The word 'risk' appears in the definition of 'practicable' in pars (a) and (b)(ii) and (iii). In s 3 of the Act 'risk' is defined to mean the 'probability' of the relevant injury or harm occurring, which means no more than the 'likelihood' of the injury or harm occurring: Hamersley Iron Pty Ltd v Robertson (18). This will require some consideration of the question of foreseeability: Chugg v Pacific Dunlop Ltd (265); Hamersley Iron Pty Ltd v Robertson (18). That, in turn, involves consideration of whether it is shown that the employer knew, or that a reasonable employer in the position of the employer would have appreciated or foreseen the risk of the injury or harm to health occurring: Wylie v South Metropolitan College of TAFE [45]; Reilly v Devcon [60]; Silent Vector Pty Ltd v Shepherd [11] - [12].

In some cases, the duty to, so far as is practicable, maintain a safe workplace may involve a consideration of matters which are beyond the employer's own area of expertise. Although the employer's duty remains unaltered, the employer's lack of direct control over such matters may affect its knowledge and, in consequence, the question of what was 'reasonably practicable' in the circumstances. This court in Reilly v Devcon [68] quoted with approval Stuart-Smith LJ's observations in R v Associated Octel Ltd [1994] 4 All ER 1051, 1063:

... the question of control may be very relevant to what is reasonably practicable. In most cases the employer/principal has no control over how a competent or expert contractor does the work. It is one of the reasons why he employs such a person - that he has the skill and expertise, including knowledge of appropriate safety precautions which he himself may not have. He may be entitled to rely on the contractor to see that the work is carried out safely, both so far as the contractor's workmen are concerned and others, including his own employees or members of the public; and he cannot be expected to supervise them to see that they are applying the necessary safety precautions. It may not be reasonably practicable for him to do other than rely on the independent contractor.

But there are cases where it is reasonably practicable for the employer to give instructions how the work is to be done and what safety measures are to be taken ...

The question of what is reasonably practicable is a matter of fact and degree in each case.

Steytler J's observations in Hamersley Iron Pty Ltd v Robertson concerning a similar duty imposed by s 9(1) of the Mines Safety and Inspection Act 1994 (WA) are also apposite here: Reilly v Devcon [64]. Steytler J said [20]:

Here, the personal duty imposed upon the employer is, as I have said, that of providing a safe workplace, so far as is practicable. If that, in turn, requires the employer to call upon expertise which it does not itself have then there is no reason why it should not do so and, indeed, every reason why it should ... If the task undertaken by the independent contractor is one which demonstrably falls within its area of expertise and outside that of the employer and if the task reasonably appears to the employer ... to have been carefully and safely performed by the independent contractor then it would ordinarily be difficult to conclude that the employer had breached the duty put upon it by the Act. It would not, in circumstances of that kind, ordinarily have been practicable for it to have done more. (emphasis in original)

See also Slivak v Lurgi (319) (Gleeson CJ, Gummow and Hayne JJ).

30 It follows that, if liable under the Act, the defendant is required to provide and maintain a working environment in which those deemed to be its employees are not exposed to hazards only so far as is reasonably practicable.

31 This will call for the making of a value judgment in light of all the facts and will be a matter of fact and degree examined as practical people, without the benefit of hindsight, but mindful of an employer's responsibility for the safety of those who work or are deemed to work for them.

32 The 'state of knowledge' relating to, inter alia, the injury, the risk of injury and the means of removing or mitigating the risk, in determining what is required by way of response is to be assessed objectively.

33 To the extent that there is a duty owed pursuant to s 13 of the Act, it is akin to the duty owed as an occupier to persons on the mine site - to exercise reasonable care for the safety of persons who it knew were likely to attend the mine. In the present case it would encompass safeguarding persons such as the plaintiff from any concealed danger such as that which may be created by the presence of bulldust-like soil in areas where persons may be required to work.

34 The plaintiff was born on 3 May 1958. He left school at a young age and worked generally in labouring positions for much of his early years. He later obtained work as a storeman at Derby Regional Hospital and a reticulation officer with the East Pilbara Shire. From 1999 to 2005 the plaintiff worked as an air-conditioning technician before commencing work with MacMahon as a truck driver on 25 March 2005.

35 The plaintiff says that when first engaged by MacMahon he was required to undergo a mine site safety induction program established by the defendant - including a 'Take 5' hazard analysis and identification program prior to being permitted to commence work on the mine site. At the time of the incident the plaintiff was one of the nominated safety representatives at the mine.

36 The plaintiff says that on 6 December 2005, while he waited for other workmen to arrive at the mine site, he decided to clean the traffic signs at the W19 intersection. He says that it was the usual practice for those MacMahon employees who lived locally to look for jobs to do until the other 'fly in - fly out' employees arrived at the site and mining operations commenced.

37 The plaintiff says that no-one instructed him to clean the signs or indeed to do any task that morning. It was the plaintiff's evidence that it was solely his decision to clean the signs at the W19 intersection and to adopt the manner of doing that task. He acknowledged in cross -examination that he had never seen anyone else cleaning the signs with a cloth whilst standing on the tyres. It was his decision to clean the signs and to use that method.

38 The plaintiff said that the signs had been erected in the tyres at the intersection at W19 prior to him commencing at the site nine months earlier. He said that he had cleaned the signs on a prior occasion.

39 Having cleaned three of the signs at the intersection, the plaintiff climbed onto the windrow of soil and then onto the stack of Haulpak tyres to clean the fourth sign using a bucket and cloth.

40 The plaintiff described the soil in the tyres holding the first three signs as firm underfoot and well compacted. The plaintiff said he stepped on to the fourth stack of tyres and began to wipe the fourth sign. The sign was fixed to a post that had been driven into the soil in the centre of the tyres and rigid. The plaintiff said the soil in the tyre was of a soft powdery 'bulldust' consistency. As he placed his full weight on the soil his right leg sank into the centre of the tyre up to his crotch - a depth he estimated to be approximately 3 feet.

41 The plaintiff said that as he tried to pull his leg out of the soil, he fell backwards off the top tyre and onto the ground below, striking his head on the ground and his right knee on a rock.

42 The plaintiff says he walked to his vehicle and drove to the administration building to report the incident and complete an accident report form (exhibit D). In that report, the plaintiff described the incident as one of being involved in a 'fall' while 'cleaning road sign'. He described the injury as a 'cut' to 'right knee'. The plaintiff says that the cut on his knee was treated at the defendant's site medical centre. He said that he was given an icepack by the site occupational health nurse for his swollen knee and calf. The plaintiff said that his knee was so badly swollen Dr Flahive was called. Dr Flahive referred the plaintiff for an x-ray of his knee and instructed him to consult his general practitioner.

43 The plaintiff saw Dr Ittermann the next day (7 December 2005) and was certified fit for restricted work until 12 December 2005.

44 The plaintiff's progress medical certificates were tendered by consent and marked exhibits 4.1 to 4.63.

45 In the medical certificate issued on 7 December 2005 (exhibit 4.1), Dr Ittermann recorded the plaintiff's description of the injury as 'painful swelling right anterior patella'. The circumstances giving rise to the injury were described as a 'fall on a rock'. Dr Ittermann's clinical findings and medical assessment was 'mild swelling r (right) ant (anterior) patella W small laceration and surrounding induration'; 'DD: injury r knee'.

46 The plaintiff was examined by Dr Ittermann on 10 December 2005. Dr Ittermann findings as to the plaintiff's medical progress were recorded in the certificate (exhibit 4.2) as 'reduced swelling/small local induration/normal ROM'.

47 On 12 December 2005, following examination by Dr Itterman, the plaintiff was certified as fit for unrestricted work. At that time Dr Ittermann recorded in what was expressed to be the 'final' medical certificate (exhibit 4.3), the following description: 'mild local inflammation/will heal/avoid hitting dashboard or else'.

48 I consider that the reasonable inference arising from the reference to 'avoiding hitting the dashboard' is that the plaintiff's complaint of injury was focused on his right knee only.

49 On 15 December the plaintiff was reviewed by Dr Ittermann. On this occasion the plaintiff reported pain in his right calf muscle. Dr Ittermann recorded (exhibit 4.4) the plaintiff's condition as follows: 'swelling r calf/r 46cm/l 44.5cm/tender r calf muscle/D Dimer +0.9'; 'DD: DVT r calf' and that it correlated with the injury described by the plaintiff. As the presence of a thrombosis was suspected, the plaintiff was certified totally unfit for work and sent to Port Hedland for further examination.

50 I note that this was the first occasion that any complaint in respect of the plaintiff's right calf was recorded in the plaintiff's medical history.

51 An ultrasound conducted on 19 December 2005 ruled out the presence of a deep vein thrombosis. The plaintiff was then certified as fit for restricted work. The plaintiff returned to normal duties but was limited to driving light vehicles and instructed to avoid prolonged sitting.

52 The plaintiff says that whilst he was able to carry out his normal driving duties, his calf would swell after a period of time. Exercise together with the wearing of a stocking was prescribed.

53 By 6 January 2006, when examined by Dr Green, the plaintiff's condition had improved and the plaintiff was certified fit to return to his pre-incident duties. Thereafter until to 17 July 2006, the plaintiff carried out his normal duties as a Haulpak driver.

54 The plaintiff says that he returned to full duties because he was aware that the MacMahon contract at Mount Whaleback was coming to an end and he was keen to ensure that he was offered a position with MacMahon at another site. He says he put up with some pain for about six months notwithstanding that his calf kept swelling up after about an hour of work and he experienced pins and needles. The plaintiff was prescribed painkillers.

55 Following an examination by Dr Skinner on 17 July 2006, the plaintiff was certified as fit to undertake restricted light work on a full time basis for the period from 25 July 2006 to 1 November 2006 - that is to say, not driving heavy vehicles. The plaintiff's reduced capacity was attributed to the effects of the medication that the plaintiff was then taking for the pain in his calf. The plaintiff was then concerned as to his capacity to safely drive heavy vehicles while taking such medication.

56 On 1 November 2006, following examination, the plaintiff was certified fit to return to his pre-incident employment, including operating a Haulpak or water cart.

57 At about this time the plaintiff was referred to Dr Desmond Williams, a consultant orthopaedic surgeon, for assessment at the request of the plaintiff's solicitors.

58 The plaintiff's account of the incident including the mechanics of his fall to Dr Williams was recorded in Dr Williams' report dated 6 November 2006 in the following terms:

He was standing on two Haulpak tyres, some 5 feet off the ground, washing a sign and he turned and put his foot in the middle of the tyre stack and fell backwards to the ground and hit the back of his head and lacerated his right knee and abrasions.

59 Following pressure tests being performed on the plaintiff's calf muscle by Dr Taylor, Dr Williams considered that the plaintiff's right calf injury was a compartment syndrome.

60 The plaintiff's description of his injury to Dr Williams was later recorded in Dr Williams' medico-legal report dated 25 January 2007 to the plaintiff's solicitors, was in the following terms:

The injury occurred when he was standing on two haul-pack [sic] tyres some 5 feet off the ground washing a sign and he turned and put his foot in the middle of the tyre stack and his leg was to calf level when he fell backwards to the ground and struck the back of his head and lacerated his right knee and had abrasions. His whole body weight therefore swung on his right leg as it was held between the two haul-pack tyres with his leg penetrating down to calf level and it was with the force of a big man falling.' (emphasis added)

61 During the period from 5 December 2006 to 7 February 2007 the plaintiff was certified by his then treating doctor, Dr Green, as being fit to undertake his pre-incident duties.

62 On 25 January 2007 the plaintiff was examined by Dr Green and certified as fit to undertake his pre-incident duties for the three-week period from 25 January 2007 to 15 February 2007. The plaintiff was scheduled to be reviewed by Dr Green on 15 February 2007.

63 On 30 January 2007 the plaintiff was informed by MacMahon that it did not have a position for him on any of its other contracts and that he was to be retrenched at the completion of the Mount Whaleback contract. The plaintiff advised MacMahon that he would not accept a redundancy.

64 On 31 January 2007 the plaintiff was retrenched by MacMahon.

65 On 7 February 2007, notwithstanding that he was not scheduled to be re-examined until 15 February, the plaintiff attended Dr Green for review. At that review the plaintiff gave Dr Green a copy of Dr Williams' medico-legal report dated 25 January 2007 that the plaintiff had received from his solicitors.

66 The plaintiff informed Dr Green that he had been retrenched by MacMahon and requested that he be certified as unfit to undertake his pre-incident duties.

67 Dr Green complied with the plaintiff's request and certified the plaintiff totally unfit for work - initially for four weeks to 7 March 2007 - and subsequently to 22 June 2007.

68 I pause to observe that Dr Green's reports and notes were tendered without Dr Green being called to testify. The certificate issued by Dr Green on 7 February 2007 recorded the date of Dr Green's examination of the plaintiff as 25 January 2007. Further, Dr Green's note of an attendance by the plaintiff on 7 March inferred that the cancellation of the certificate of fitness dated 25 January 2007 was premised on the plaintiff having been made redundant (exhibit 5.7 page 12).

69 This aspect of the evidence not addressed during the plaintiff's case. The possibility of an adverse inference being drawn was brought to the attention of those representing the plaintiff. In accordance with observations of the High Court in Kuhl v Zurich Financial Services Australia Ltd [2011] HCA 11[69] - [72], I allowed the plaintiff's application to re-open his case to adduce evidence from Dr Green. I shall refer to Dr Green's evidence more fully later in these reasons.

70 The thrust of Dr Green's evidence was that there was no change in the plaintiff's physical state or working capacity from 25 January 2007 (when he certified the plaintiff as fit for his pre-incident employment) and when he reviewed the plaintiff on 7 February 2007. Dr Green said that he issued the certificate on the basis of the contents of Dr Williams' letter to the plaintiff's solicitors and, more particularly, the fact that the plaintiff had been made redundant notwithstanding that he may still require physiotherapy and other treatment to be paid for.

71 The plaintiff was recalled for further cross-examination on this issue. The plaintiff acknowledged that he had provided a copy of Dr Williams' letter to Dr Green and that he requested Dr Green to certify him as unfit for work. The plaintiff said he did so because he thought that 'compo covered redundancies. They (MacMahon) still had to pay me'. The plaintiff further acknowledged that he was then aware that Dr Williams had recommended relatively minor treatment limited to include swimming, stretching and strengthening exercises with the possibility of some local physiotherapy.

72 In February 2007, the plaintiff considered that he should have been given a new position with MacMahon and, further, that he could not be made redundant while he was certified as unfit to engage in his pre-incident employment. Thereafter the plaintiff commenced proceedings in the Australian Industrial Relations Commission (AIRC) against MacMahon for wrongful dismissal.

73 Inconsistencies in the plaintiff's account of the incident at trial and his witness statement dated 8 May 2007 filed in the AIRC proceedings (exhibit B) were put to the plaintiff in cross-examination.

74 In pars 16 and 17 of his statement (exhibit B) the plaintiff described the incident as follows:

After I cleaned the third sign, I walked along the windrow of soil between the third and fourth signs and I walked on top of the tyre of the fourth sign, which was approximately 2 feet wide and had washed the sign.

At around 7:30 am I finished cleaning the fourth sign. I then turned around and placed my right leg inside the tyre onto the soil, with the intention of walking across the soil to get to the other side of the tyre. However, as I stepped into the soil, my right leg sunk into the soil up to my right knee. As I went to pull my right leg out, I lost my balance and fell backwards onto the main haul road, hitting the back of my head and hitting my right knee on a rock on the road. When I fell, I ripped the backside and the right knee of the trousers I was wearing at the time.' (emphasis added**)**

75 When cross-examined in relation to the inconsistency with his evidence at trial, the plaintiff's evidence was as follows:

CLYNE, MR From where - from where you're standing now. Assume that you've got the sign - - ----Well, the sign's there.

Yes---I turned around - - -

Yes---- - - lost balance, placed my right leg in the tyre, sunk to my crutch, panicked, pulled my leg out and head over turkey I went, below.

You're sure you went down that far---I sure did. I had the sand marks. I blew the back side out of my strides and ripped all my leg and my strides.

Isn't it the case you only went in up to your knee---No.

All right. You hadn't - do you agree that - sorry. Have you ever said before that you went in up to your knee---I might have, yes.

But - - ----But I think you'll find if you look through the records I also stated crutch.

All right. Now, perhaps, then, we ought to look at a witness statement that you gave through your solicitors to the workers' compensation directorate. One for your Honour, one for the witness and one for my friend. Now, firstly, down the bottom, is that your signature on the first page---Yep.

Second page, third page, fourth page, fifth, sixth and finally on the last page---Yep.

And as we can see from the last page, this was signed by you on 8 May 2007---Yep.

Correct---Yep.

And you recall this was prepared at a time when you were trying to get workers' compensation payments---Yes. Maybe, yeah. (ts 114 - 115)

The plaintiff's cross-examination continued (ts 120).

CLYNE, MR: Around 7.30 I'd finished cleaning the fourth sign and then turned around and placed my right leg inside the tyre onto the dirt with the intention of walking across the dirt to get to the other side of the tyre. Is that right---Yeah, it could have been. Yes. Yes.

And you then say, and just read this carefully: However, as I stepped into the dirt, my right leg sunk into the dirt up to my right knee.---Mm.

Knee---Yep.

Not thigh---Yeah.

Now, this is a statement you made 3 years ago---Mm.

I suggest that your recollection then was better than it is now---Well, it most probably was, yeah.

So you only went in up to your knee---No, I'm certain I said crutch in other statements or somewhere.

76 In late May 2007 the plaintiff moved from Newman to Perth. Up until that time the plaintiff had continued to consult Dr Green and was certified as totally unfit for work.

77 In July 2007 the plaintiff consulted a new GP, namely Dr Koh. Dr Koh continued to certify the plaintiff unfit for work.

78 In August 2007 the plaintiff was reviewed by Dr Home, at the request of MacMahon's solicitors and assessed for workers' compensation purposes.

79 Dr Home's unchallenged record of the plaintiff's description of the incident detailed in his report dated 27 August 2007 (exhibit G1, page 6) was as follows:

Mr Smith states that at the time of the accident, he was working as a truck driver for MacMahon's. He was undertaking duties cleaning the signs. The signs were positioned over a windrow that was held in place by four Haulpak tyres, that is two stacks of two, lying at either end of the windrow. He was standing atop of one of the tyre stacks cleaning a sign when he placed his foot into the centre area of soil in the middle of the tyre. He anticipated that the soil would be compacted but it was not so. He tells me that his leg penetrated the softer soil to the level of his groin.

He then managed to extract his leg but lost his balance and fell off the top of the tyre stack, landing over his right side and in particular striking the front of his right knee. He recalls further abrasions to his nose and chin. (emphasis added)

80 I note that this was the first occasion that the plaintiff asserted that he sank to the depth of his groin (or crutch) - such statement being made approximately 20 months after the incident and three months after his witness statement (exhibit B) in the AIRC proceedings.

81 In September 2007 the plaintiff undertook a work trial as a storeman. This was done as part of his rehabilitation organised by Workfocus Rehabilitation Agency.

82 In October 2007 the plaintiff undertook a one-day forklift course, and was certified as fit for restricted return to work.

83 In December 2007 the plaintiff underwent vocational assessment.

84 In January 2008, the Plaintiff was certified by Dr Koh as unfit to drive a truck for two years.

85 In February 2008 the plaintiff commenced a work trial with Peters Discount Salvage working as a storeman.

86 On 18 February 2008, seemingly upon becoming distressed that he was the subject of covert surveillance by assessors on behalf of MacMahon's workers' compensation insurers, the plaintiff attempted suicide. The plaintiff was admitted to Armadale hospital. He was discharged later that day. Thereafter the plaintiff continued to undertake a restricted work trial with Peters Discount Salvage until the funding available for assisted work rehabilitation was exhausted in June 2008.

87 The plaintiff has not engaged in his pre-accident occupation, nor unrestricted employment in any other capacity since being certified as being unfit to do so by Dr Green on 7 February 2007.

88 The plaintiff as a 53-year-old man with limited education is seemingly not unintelligent and was fully appreciative of the issues involved in the trial of this matter and the importance of his account as to the circumstances relating to the incident.

89 The plaintiff is the only witness in respect of the events that occurred on 6 December 2005 and I need to be satisfied as to the truthfulness, reliability and accuracy of his account.

90 The plaintiff's account as to the circumstance of the incident and, particularly the depth to which his leg is alleged to have sunk into the soil in the tyre has varied considerably over time.

91 In the amended statement of claim filed in September 2009, the incident is pleaded in terms:

... The Plaintiff then proceeded to clean the fourth sign and placed his right leg onto the soil inside the two Haulpak tyres and unbeknown to the Plaintiff, the soil was not compact or solid and did not support the Plaintiff's weight, resulting in the Plaintiff's right leg sinking into the soil and the Plaintiff lost balance and fell from a height of about 5 feet onto the ground below.

92 Significantly there is no reference to the depth that his right leg sank into the soil or that he fell as he attempted to extract his leg. It is assumed that the pleading is drawn in accordance with the plaintiff's instructions.

93 In the incident report (exhibit A1) the plaintiff's account of the incident as recorded by MacMahon employees based upon information provided by the plaintiff mentioned that the soil was comprised of 'bulldust'. Significantly, there was no reference to the plaintiff's leg having penetrated into the soil in the manner alleged. Further, the fact that the plaintiff's leg penetrated the surface of the soil in the tyre was not mentioned at all in the incident report completed by the plaintiff on the day it occurred (exhibit D). The plaintiff described the incident as a 'fall' causing him to 'cut his right knee'.

94 If the incident had occurred in the manner described by the plaintiff, one could reasonably expect that he would have described it in such terms when first seeking medical assistance and advising as to the mechanics of the injury suffered. Given that the plaintiff was a nominated site safety officer for MacMahon who, on his account had encountered a workplace condition that he described as a dangerous concealed hazard, it is astonishing that it was not reported and described in detail by him at that time.

95 Further, the circumstance of the incident alleged was not mentioned in Dr Williams report dated 6 November 2006. The first documented report is found in the report of Dr Williams dated 25 January 2007 wherein it is recorded that the plaintiff's leg had sunk to 'calf level.'

96 In May 2007, the plaintiff deposed in the AIRC proceedings that his leg had sunk to a depth of 'up to my right knee'.

97 When examined by Dr Home in August 2007 the plaintiff said that his leg had sunk into the soil 'up to his groin'.

98 At that time the plaintiff then had a copy of Dr Williams' report in which the significance of the relationship between the mechanism of the injury and the diagnosis of compartment syndrome had been noted.

99 The plaintiff's description of the incident at trial was to the effect that he sank to the full length of his leg, 'up to his crotch' in the powdery soil.

100 The plaintiff is a tall man. To suggest that the soil was so powdery and loose that the plaintiff's right leg could penetrate the surface of the soil in the tyre (in which the sign and post is rigidly held in position) to a depth of almost a metre strains credibility. It is wholly against the probabilities.

101 I do not accept that the plaintiff could honestly believe that the incident occurred as he described. I do not accept his evidence at trial was a truthful account of the incident. I consider that the plaintiff was grossly exaggerating the incident and its effect. His various accounts as to the depth his leg is said to have sunk into the soil are inconsistent and unreliable.

102 Further, the fact that the plaintiff requested Dr Green to certify him as totally unfit in February 2007 to facilitate his recovery of workers' compensation entitlements - notwithstanding his redundancy - when he must have then known that there was no change in his physical condition or capacity to work impacts on his credit and reliability as a witness of truth.

103 I consider that his motivation for requesting the change to the fitness certificate was premised on his redundancy and the belief that he was being unfairly treated by his employer. I am fortified in that view by the fact that the plaintiff thereafter considered himself to be wholly unfit - that is to say, unable to undertake any work whatsoever and pursued a wrongful dismissal claim in which he significantly exaggerated the circumstances of the incident.

104 Throughout this period the plaintiff did not undertake the exercise regime recommended by Dr Williams in January 2007 that seemingly offered resolution of his injury and proceeded to challenge his retrenchment by MacMahon on the basis that he was incapacitated from engaging in his pre-incident employment or indeed, any employment whatsoever.

105 In my opinion such conduct demonstrates that the plaintiff was prepared to be untruthful in an effort to bolster or support a claim in respect of an injury that did not otherwise preclude him from continuing full time in his pre-incident occupation.

106 I was left with the impression that the plaintiff's exaggerated description of the incident and severity of the trauma on his calf, particularly in relation to the depth that his leg penetrated the soil, was directed to providing support for Dr Williams' diagnosis in respect of a calf injury that was not readily apparent upon clinical examination and did not otherwise physically prevent him from continuing in his pre-incident occupation in January 2007 had he had not been made redundant.

107 Further, as observed by Dr Home in his report of 23 January 2008 (exhibit G3 page 1), there is an inconsistency in the plaintiff's reported difficulty in driving for extended periods such that it resulted in him being certified by Dr Koh in January 2008 as unable to drive a truck for two years notwithstanding that, the plaintiff, who then resided in Forrestfield, drove some 50 km to Hillarys to consult Dr Koh.

108 I consider that if the incident had in fact occurred in the more dramatic manner as it is now described by the plaintiff, one could be confident that the plaintiff would have described it in such terms when first seeking medical assistance and reporting the mechanics of the incident and how his injury occurred.

109 The fact that the plaintiff sought to maintain the erroneous description of the mechanism of his fall and seemingly embellish it over time goes to his credit generally. I formed an unfavourable view of the plaintiff's evidence and do not regard it as reliable or, in several instances, truthful. I find that his evidence in relation to the circumstances of the incident on 6 December 2005 to be incapable of acceptance by me. In the absence of credible supporting evidence that is accepted by me I am not prepared to accept the plaintiff's evidence on any matter.

110 Mr Lee was employed by MacMahon's as a truck driver at the mine site in 2005.

111 Mr Lee said that he specifically recalled the day of the incident when the plaintiff was injured. He said that the superintendent, Mr Seymour, had instructed him to drive the water cart and the plaintiff to take a specified light vehicle and go and clean the signs. Mr Lee said that he had seen MacMahon's employees clean road signs in the past.

112 In cross-examination Mr Lee said he had a clear recollection of that day as 'it was the day a work colleague was injured'. Mr Lee said that the plaintiff had told him about the incident shortly after he had returned from seeing 'God' - a derogatory reference to his superintendent Mr Seymour. Mr Lee gave the impression that he neither liked nor respected Mr Seymour for whatever reason.

113 Whilst Mr Lee was adamant that the plaintiff had been instructed to clean signs by Mr Seymour, such evidence does not accord with the plaintiff's account. I gained the impression as Mr Lee gave his evidence that he was keen to assist the plaintiff's case with his testimony. Mr Lee's evidence was inconsistent with the plaintiff. Further, given that the nature and extent of the plaintiff's calf injury was seemingly not apparent until several days after the event, Mr Lee's explanation as to the reason why he remembered the event with such clarity is improbable. I consider Mr Lee's evidence unreliable and accord it little weight.

114 In December 2005 Mr Jess was employed by the defendant at Mount Whaleback as a contract superintendant. Together with Mr Ian Garnett, Mr Jess was engaged by the defendant to, inter alia, undertake daily inspections of MacMahon's work area and ensure compliance with the requirements of the mine operations contract and management plan.

115 Mr Jess said that one aspect of the work safety procedures required by the defendant and implemented by MacMahon included recording any likely 'lost time' incidents. As part of that process the document headed 'Confidential event report' dated 19 December 2005 (exhibit A1) relating to the incident involving the plaintiff was completed. Mr Jess said that the form was used to record data in respect of any type of incident that occurred on the site whether it was safety, environmental or community related. It was an electronic database that allowed the defendant to store data and later review practice and safety performance. As the incident involving the plaintiff related to a MacMahon matter, the defendant's staff entered the relevant information into the data base (as recorded on exhibit A1) with input from various sources including the MacMahon's safety department.

116 In the section entitled 'treatment details by person' the treatment received by the plaintiff was described as:

[C]leaned wounds with Chlorhexidine and Cetrimide, applied Steri-Strips, dressing, ice for 20 mins to right calf muscle, Nurofen x 2, Voltaren Gel, compression bandage.

117 In the section in the document headed 'investigation findings', the 'long description' of the incident is expressed in the following terms:

After cleaning for signs located on the road dividers, all of which had hard centres (filled with the dirt), Wayne stepped inside the offending tyre which was filled with bulldust (which wasn't easily noticed) and fell onto the dirt and then over the side landing his knee on a rock.

118 Mr Jess said that, as the incident was then believed to be minor and did not involve any lost time, no independent investigation was undertaken. Accordingly the information entered in exhibit A1 was based on that provided to the defendant by MacMahon employees and was dependant on the plaintiff's description of the incident.

119 The entry for 'root cause' on page 2 of exhibit A1 was entered on 12 December 2005. The cause nominated by the MacMahon's employee was 'broom was not available to complete the task which meant that the job was done by standing on the tyre'. It was recommended that a long-shank broom be used instead of climbing over windrows and that brooms be made available. The document records that such recommendation was made and had been addressed at that time.

120 Mr Jess said he was aware MacMahon had subcontracted the construction and maintenance of the haul roads - including the cleaning and maintenance of road signs - to Mr Len Terry of Dynamic Earthmoving ('Dynamic').

121 Mr Jess said that it was a matter for MacMahon if they wanted to break up the mining operations into subcontract arrangements. So far as the defendant was concerned, any subcontract arrangements that MacMahon had with another contractor was treated as if it was part of the original mine operations contract work that was being carried out by MacMahon for the defendant and supervised accordingly. Mr Jess said that it was unnecessary for MacMahon to obtain the defendants approval to subcontract part of the works provided the subcontract agreement required that the works were carried out upon the same conditions and standards as those contained in the mine operations contract and that the works were managed within the scope requirements of the original contract. This included all safety aspects.

122 Mr Jess said that the mine operations contract specified the contractual standards required by the defendant for the performance of the work. Thereafter a system of work was developed to ensure that those contractual requirements were delivered.

123 Mr Jess said that pursuant to the mine operations contract MacMahon was required to submit a safety management plan to the defendant for its approval. Such plan was to detail the safety system which would be introduced in the performance of the work and to contain procedures to ensure that MacMahon complied with the Act including issues concerning health and safety. It further required plans for traffic management at the site.

124 Mr Jess said that the defendant had no input into the design, development and maintenance of the road system but did specify the required safety standards to be observed. Mr Jess said that as part of the plan, MacMahon was required to ensure that traffic signs were kept in a clean and effective working order. MacMahon was further required to provide an equivalent level of safety to enable that process to be undertaken.

125 Mr Jess said the defendant relied on MacMahon as the mining contractor who specialised in the scope of work to undertake all of the mining operations required by the mine operations contract.

126 Pursuant to cl 2.10 - cl 2.14 of the mine operations contract the defendant was permitted to carry out audits to ascertain MacMahon's compliance with its health and safety obligations under that contract and direct that corrective or preventative actions be taken by MacMahon in the event of any non-compliance being observed.

127 Mr Jess said there was a rigorous process in place where the performance of MacMahon was reviewed, including daily, weekly and monthly meetings. In addition to weekly meetings involving Mr Jess and Mr Ian Garnett on behalf at the defendant and the management team of MacMahon, there were also daily meetings to review any safety aspects to ensure safe and efficient operation of all mining activities on the site each day. The defendant also required MacMahon to complete safety inspections of every area prior to each shift that an employee was likely to work during that process. There were also regular daily audits and safety inspections conducted by the defendant to supervise and monitor the activities occurring on the site to ensure compliance with the mine operations contract.

128 Mr Jess said that he, together with Mr Ian Garnett, would regularly inspect and review the mine site area. In the event of any non-conformity with the contractual obligations or unsafe practises being observed giving rise to an immediate danger to people, equipment or infrastructure, the job would be stopped. In respect of other issues that did not give rise to an immediate threat or danger, either he or Mr Garnett would communicate the matter to the MacMahon project management team for its attention and correction. Mr Jess said that if MacMahon's project management team was informed of any defect or deficiency that the defendant required to be addressed there would be follow-up or supervision to ensure that the request was addressed.

129 Mr Jess was familiar with the intersection W19. He said that the tyres, waste soil and signs depicted in the photographs in exhibit A8 were representative of those that had been at the W19 intersection in December 2005, including the soil material in the tyre depicted in exhibit A8 at page 145. Mr Jess said that the traffic signs were erected by a stake or post being driven into soil that had been placed inside the Haulpak tyres. A pipe with the sign attached was then placed over the top of the stake and driven into the ground to secure it.

130 Mr Jess rejected the plaintiff's contention that very fine particled earth or 'bulldust' had been placed in the tyres at W19 intersection. Mr Jess said that if talc-like material such as bulldust was used inside the tyre in lieu of competent soil the sign would be blown over by the first gust of wind.

131 Mr Jess impressed as a careful witness whose credibility and reliability was not seriously challenged or questioned to any effect. I have no hesitation in accepting his testimony.

132 In January 2007 the plaintiff was examined by sports physician Dr Gerard Taylor. Dr Taylor's reports were tendered as exhibits 8.16, 8.17 and 8.18.

133 Dr Taylor conducted compartment pressure measurements and noted that the affected area of the plaintiff's right calf measured pressures in excess of 90 mm of mercury (HG). He considered the measurements in excess of 90 mm of HG were well above the upper limit of normal. In his opinion the findings were suggestive of localised gastrocnemius trauma producing a localised area of compartment syndrome. Dr Taylor considered that if an MRI identified such pathology upon testing, surgical intervention may be warranted.

134 In Dr Taylor's experience as a sport's physician, surgery for such condition was generally successful and in the case of athletes usually enabled them to return successfully to competition.

135 The radiological report of Dr Nick Dale dated 19 January 2007 was tendered (Exhibit 8.41). Dr Dale recorded that post exercise images showed no change from the pre-exercise images and that there was no MRI evidence of compartment syndrome. He opined that the absence of MRI evidence did not necessarily exclude a compartment syndrome.

136 Dr Desmond Williams, a consultant orthopaedic surgeon, saw the plaintiff on 30 October 2006 and 1 November 2006 for medico-legal purposes.

137 I have referred earlier in these reasons to Dr Williams' account of the plaintiff's description of the incident upon which Dr Williams' assessment is founded.

138 Dr Williams said that he initially suspected that the plaintiff had suffered a compartment syndrome and referred the plaintiff to Dr Taylor for pressure tests. Dr Williams said the test results showing increased pressure in the right calf muscle confirmed his opinion although the subsequent MRI results from Dr Dale were equivocal.

139 Importantly, Dr Williams considered the diagnosis of compartment syndrome was consistent with the mechanism of the injury as described to him by the plaintiff whereby the plaintiff's leg dropped into the soil and was held as his body weight flung back with the calf area suffering a traction type injury and a stress strain to the tissues.

140 When cross-examined as to the mechanism of the plaintiff's injury, Dr Williams described the plaintiff's fall in the following terms:

CLYNE, MR: The injury occurred when he was standing on two Haulpak tyres, some five foot off the ground, washing a sign and he turned, then put his foot in the middle of the tyre stack and his leg was to calf level. So he told you his leg went into calf level---Yeah, his leg went down so that the calf was level with the edge of the tyres.

...

CLYNE, MR: Now, his leg was to calf level, when he fell backwards to the ground and struck the back of his head. Now, when you've been saying that the --- Sorry.

So you're just checking your notes to make sure that's accurate are you, doctor --- Yeah, I mean, I'm just wanting you know, whether I said anything different here - unless I took it down. But please go on, it's the same sort of story, yeah.

All right. I just want to get your understanding. His leg was to calf level when he fell backwards and struck his - the back of his head and lacerated his right knee. Now, you've said that there was a direct contusion or a traction injury. Do I understand what you're saying is that he still had his leg stuck when he fell ---Yeah, I've got - I believe he was on the tyres.

Yes --- Leg dropped in between the round part of the tyres. Then he fell backwards and his calf impacts the edge of those tyres, but the leg doesn't stop there, because he goes back and hits his head.

CLYNE, MR: Right. You're not saying his leg was stuck in there obviously, because he's not that tall---No, because he's - he went on. It was stuck for a period and then as it flipped over, it wasn't stuck.

Right. Now, as I understood his evidence, it was that it was when he pulled his leg out that he fell backwards and he overbalanced and fell. So he'd actually pulled it out, that's his evidence that I --- Well, in - as I understood it, it was all one thing. Whether he thinks he pulled it out or it happened when as he went back, it's a variation of seconds, I think.

All right. Now, you say his whole body weight therefore swung on his right leg, as it was held between the two haulpak tyres. That's - if you just read there on page - - ----Yeah, I'm - I'm saying, it's there. He goes back and the leg comes out.

How is his whole body weight ---Well, as he's falling back, his body weight's going back and his calf's hitting the edge of the tyres.

Right --- And then his leg comes up and out and he goes right, it tips out and hits his head.

But if his leg came out first, you wouldn't have the traction stretching injury, would you ---Well, yeah. It's - it's not - it's not sort of leg straight out and no - he's got his leg in there. It's impacting the back of the tyres and the front of the tyres as the leg comes out.

But if his leg --- And his whole body weight's going back and he's stretching into extension. I see traction there.

He's hold - if his leg was out and that caused him to overbalance, there's no traction on the calf muscle, is there --- Well, how do you mean his leg's out, you know.

- - - he went down and he lifted it out --- And where's his head at this point?

Above him, apparently --- Well, I think it's halfway down at that point.

Or halfway down. Doesn't matter --- Well, halfway down - - -

CLYNE, MR: We don't have - - ----Halfway down gives him the traction that we're talking about.

Only if the leg's still in there, are you saying --- No, he has traction unless he's sitting on the edge of the tyres and lifts his legs out. I don't believe he was sitting on the edge of the tyres.

And again you say there that his leg was penetrating to calf level. So you've said that on two occasions --- Yeah, but the calf's the thing that hit the edge of the tyres as he came out. (ts 225-226)

141 In his second report, Dr Williams seemingly placed considerable importance on the mechanics of the injury to support the diagnosis of compartment syndrome and that the injury was considered incident related. This is evidenced by the fact that, following the pressure test results, Dr Williams amended the plaintiff's reported description of the incident in his report dated 25 January 2007 (exhibit 8.24) as follows:

The injury occurred when he was standing on two haul-pack [sic] tyres some 5 feet off the ground washing a sign and he turned and put his foot in the middle of the tyre stack and his leg was to calf level when he fell backwards to the ground and struck the back of his head and lacerated his right knee and had abrasions. His whole body weight therefore swung on his right leg as it was held between the two haul-pack tyres with his leg penetrating down to calf level and it was with the force of a big man falling. (emphasis added).

142 I observe that the passage highlighted above was seemingly added to Dr Williams' reporting of the plaintiff's description of the incident from that in his earlier report to provide a causal link between the plaintiff's injury and the reported mechanics of his fall. As noted earlier in these reasons, the plaintiff's initial description as reported by Dr Williams in November 2006 omitted any reference to the plaintiff's leg penetrating the soil (or the depth) and was not mentioned as a contributing factor to the plaintiff's injury.

143 Dr Williams considered that the result of the trauma gave a stress strain to the muscle resulting in a low grade muscular myofascial strain, that is to say, the sheath covering the muscle that connected the muscle to the tendon.

144 Dr Williams said that in January 2007 the then appropriate treatment for the plaintiff was swimming, stretching, strengthening and some local physiotherapy using ultrasound and inferential technique to settle the residual irritability and that at that time he had identified the treatment required. Dr Williams said that the plaintiff's rehabilitation was seemingly absent or poor and that had the plaintiff symptoms been treated as recommended by him they would have resolved.

145 Referring to video surveillance film of the plaintiff taken in May 2007 Dr Williams said the video simply showed that the plaintiff was doing simple activities and not stressing his calf in a heavy way or repetitive way. Dr Williams considered that the plaintiff could work as a forklift driver or in a similar capacity.

146 In June 2007 Dr Williams assessed the plaintiff's degree of permanent impairment as being 2% of the right lower limb, equating to 1% of the whole person impairment.

147 In his report dated 20 January 2009 (exhibit 8.38) Dr Williams noted that upon clinical examination of the plaintiff, calf measurements taken at 10 cm below the patella, the left gastrocnemius was 42 cm and the right 43 cm. At 15 cm below the patella, the left was measured at 43.9 cm and the right at 44 cm showing little by way of measureable difference in calf circumference.

148 I observe that on 15 December 2005, (9 days after the incident) when the swelling of the calf was first reported to him, Dr Ittermann recorded the plaintiff's calf diameter measurements of 46cm to the right calf and 44.5cm for the left calf (exhibit 4.5) - a difference of 1.5 cm.

149 Dr Williams said that by 2010 as the plaintiff's injury had not been acknowledged (seemingly by his former employer's insurers) and was being attributed to diabetes and other issues such that no-one wanted to treat him or give him treatment advice. At that time Dr Williams assessed the plaintiff's impairment in terms of the AMA Guidelines. Dr Williams considered it was not easy to make an assessment, however, agreed that the assessment of the plaintiff by Dr Fong, an occupational physician, as having 5% whole person impairment based on physical aspects and 5% based on psychological was a fair assessment.

150 Dr Williams said his assessment of the plaintiff's return to work focused on intensive rehabilitation efforts centred on swimming, exercise schedules and stretching programs simply dealt with the muscle contusion injury - the soft tissue elements of the injury.

151 It was Dr Williams' evidence that the neuropathic pain, which subsequently emerged as a more significant problem, could have been treated with Lyrica if the plaintiff had undertaken a course of exercise, swimming or stretching, as recommended by him in January 2007. In his opinion, had this course been followed the plaintiff's calf injury would have been resolved by mid 2007. He said that once the plaintiff's pain became chronic, it was a more difficult neuropathic problem to deal with.

152 Dr Williams considered that the denial of the plaintiff's injury by MacMahon's insurers was a significant factor. He considered that the effect of rushing to get the plaintiff back to work and disregarding the plaintiff's reported symptoms was such that the plaintiff's symptoms became chronic. Dr Williams said that with the chronic nature of his symptoms came the depression where the plaintiff felt he was going in circles and not getting anywhere.

153 At trial Dr Williams agreed that the plaintiff's condition had improved since he first saw him in 2006 and that the plaintiff should have been doing some exercise, reducing his medication and getting on with his life. Dr Williams observed however that since the plaintiff had first consulted him he had seemingly made little effort to do so.

154 Dr Williams considered that surgical decompression of the affected area may not be effective in the absence of evidence of localisation of the compression.

155 I am troubled by Dr Williams' decision to omit from his report in November 2006 the more complete account of the plaintiff's description of the mechanics of the incident including the reference to the plaintiff's leg penetrating the soil (or the depth) and/or that it was a contributing factor to the plaintiff's injury. At the time of his earlier report, Dr Williams then suspected a compartment syndrome and had referred the plaintiff to Dr Taylor for pressure tests and for the MRI. If the factual circumstance was considered important by Dr Williams it is reasonable to expect that it would have been referred to earlier.

156 If it was not significant, the inclusion of it in the subsequent report was unnecessary other than to bolster a diagnosis that is not otherwise supported by clinical examination - save for a single pressure test in 2006 that has not since been repeated.

157 Dr Williams has seen the plaintiff for medico-legal purposes only. To the extent that Dr Williams seemingly relies upon the plaintiff's account of the incident and his description of his injuries for the purposes of assessment and opinion, and mindful of my assessment of the plaintiff's credibility generally, I approach Dr Williams' evidence with caution.

158 The plaintiff's wife, Mrs Yvonne Smith said that immediately following the incident the plaintiff had a swollen calf muscle. Mrs Smith was adamant that on the night of the incident when she picked up her husband from the bus stop it was his right calf that he was concerned about. She said that his calf was swollen to such extent that she had to cut his trousers off.

159 When challenged in cross-examination as to her recollection as to when the plaintiff identified a problem with his right calf, it was apparent that Mrs Smith relied on the contents of various medical reports prepared by others to assist her recollection of the events. Her evidence was:

CLYNE, MR: Mild local inflammation, will heal. Avoiding hitting dashboard, else.

And I suggest that if it was his calf, he's unlikely to hit the dashboard with it. So again I'm suggesting to you that the initial week, all of the medical reports were for the right knee, and that there's no mention of the calf, and that therefore your recollection of the calf being an initial injury is wrong?---It was his right calf. I don't - I don't - I've not seen - yeah.

All right. The calf------I don't know about the hitting the dashboard and whatever, but it was his right calf. That's---

Well, the calf - go on, sorry. Sorry to interrupt---Yeah, it was his right calf that I had dealings with and saw when he came off that bus, when he was at home and if that's the case, why would they apply ice to his right calf at---

Well, how do you know they applied ice to his right calf---Because that's on one of the documents. (ts 251)

160 Having regard to the manner in which the plaintiff reported the history of his injury, as recorded in contemporaneous documents, including the initial incident report (exhibit D) and the progress medical certificates - particularly to exhibits 4.1 to 4.5, I do not accept Mrs Smith's evidence in relation to this matter. In particular, I do not accept that the plaintiff's calf was swollen to such extent that she was required to cut off his trousers. I consider that it is more probable that the plaintiff's knee was swollen - particularly given that Dr Flahive had been called to treat him and had requested that the plaintiff have his right knee x-rayed. If there was a significant injury with swelling to the plaintiff's calf it is reasonable to expect to find some reference to such fact in the contemporaneous document or treating notes.

161 Mrs Smith said that following the accident the plaintiff was no longer able to do the domestic tasks as he had previously done, that the heavy medication was making him tired and that his leg would swell up. Mrs Smith said that the plaintiff would previously assist with vacuuming and general tidying up. Mrs Smith said that since the incident, she is required to do approximately five hours additional domestic chores per week to make up for that which would have been previously done by the plaintiff.

162 I considered Mrs Smith, not unnaturally, to be sympathetic to the plaintiff's complaints. In the light of my earlier observations in respect of the plaintiff's credibility - I do not place great weight on her evidence.

163 In July 2007 the plaintiff moved from Newman to Perth and consulted Dr Koh as his general practitioner. Dr Koh's reports and certificates were tendered as exhibits 8.5 to 8.8.

164 In his report to the plaintiff's solicitors dated 31 January 2009 Dr Koh records the plaintiff's description of the circumstances of his injury in the following terms:

He said he was standing on tyres to clean a sign when he fell heavily to the ground, injuring his right knee, nose and chin. A week later, he experienced pain and noticed swelling in his right calf and knee joint. Though his right knee was better, his right calf pain persisted ever since, with pins and needles sensations. The pain was described as sharp shooting type, travelling along the medial aspect of the right knee and leg. (emphasis added)

[R]esponded well to the medication called Neurontin which is very effective in relieving neuropathic type of pain coming from injured nerve tissue, which is what Wayne has. Unfortunately he had to take high dosage of this drug which made him drowsy and feeling dizzy. He had to stop it as a result.

166 Dr Koh prescribed the drug Lyrica to assist the plaintiff with his pain.

167 On 15 January 2008, Dr Koh certified the plaintiff as then unfit to drive a truck for two years from 15 January 2008, due to the pain in the plaintiff's right calf being aggravated by prolonged driving. [I observe that this certificate was issued by Dr Koh six months after the plaintiff first became his patient and seemingly assumed that the plaintiff was not going to respond to any treatment for a further two years, that is to say until January 2010.]

168 In April 2009 Dr Koh certified that the plaintiff was fit to drive private vehicles but unfit to drive commercial vehicles. [I further note that in completing such certificate Dr Koh certified that he had attended upon the plaintiff professionally for three years. The plaintiff did not consult Dr Koh until July 2007- less than two years earlier.]

169 Having initially said that no medications for other ailments had been prescribed to the plaintiff, when pressed in cross-examination, Dr Koh, after some hesitation confirmed that he had also prescribed medications to treat the plaintiff's hypertension, cholesterol and diabetes.

170 When referred to Dr Williams' recommendation that the plaintiff continue with physical rehabilitation based on swimming and exercise schedules and a return to work, Dr Koh was unsure whether he was aware of the recommendation but confirmed that the plaintiff had always been told to carry on with exercise and attend physiotherapy. He further confirmed that by 2010 the plaintiff had improved his psychological position.

171 Dr Koh's seeming reluctance to reveal the extent of the plaintiff's non-incident related medical condition and the inaccuracies in his certification of the plaintiff's unfitness to drive heavy vehicles impacts on his evidence such that I am not prepared to accept or rely on it unless it is supported by witnesses whose evidence I do accept.

172 Dr Manners is a specialist psychiatrist to whom the plaintiff was referred by Dr Koh in January 2009. Dr Manners said that it is apparent from the history of the plaintiff that after he injured his leg, he developed a depressive syndrome which was related to his injury and his loss of work. He said that the plaintiff's symptoms had increased and become more sustained such that it could be described as a major depressive disorder.

173 Dr Manners said that if the plaintiff's physical injuries were resolved he would not be prevented from returning to work from a psychological perspective.

174 At the date of trial Dr Manners considered that the plaintiff was then depressed with features of a depressive episode although he considered that the trial may have had some impact on his state.

175 In cross-examination Dr Manners said that prior August 2010, he considered that the plaintiff merely suffered from an adjustment disorder, that is to say stresses of adjusting from having previously worked to being affected by injury and no longer working rather than any depressive episode. He said that the symptoms he observed of sleeplessness, irritability, reduced tolerance, depression, withdrawal and avoiding people was such as to classify the plaintiff as having suffered a major depressive episode.

176 Dr Manners was confident that if the plaintiff's injury to his calf was able to be resolved, the plaintiff could return to work in any event. Dr Manners was satisfied that the plaintiff taking medication for his depressive condition would not impact upon the plaintiff's ability to work as a Haulpak driver.

177 Dr Fong is a specialist in rehabilitative medicine. His reports dated 12 April 2010 and 18 August 2010 (exhibits 8.2 and 8.4) were tendered.

178 Dr Fong saw the plaintiff on 16 March 2010 for the purposes of preparing a medico-legal report. He said his assessment of the plaintiff was based upon information provided by the plaintiff without the benefit of any tests in relation to weight restrictions.

179 Dr Fong considered that the plaintiff was physically precluded from ever returning to regular employment as a truck driver. This assessment was based on his understanding that the plaintiff's heavy truck driving licence had been revoked on medical grounds and it would be unlikely that his physical or emotional condition would allow him to safely return to that field of employment in the foreseeable future.

180 I observe at this time that the revocation of the plaintiff's licence was seemingly based upon the report of Dr Koh in January 2008 to which I have referred earlier in these reasons.

181 Dr Fong considered that it was unlikely that the plaintiff would be capable of continuing with any form of employment beyond age 60. He anticipated that the plaintiff's chronic leg pain would progress and limit his mobility. Dr Fong considered that the additional factors including the plaintiff's chronic neck and lower back pain symptoms and his diabetic condition together with vascular disease affecting his lower limbs and cardiovascular system would further deteriorate and preclude him from working. Dr Fong considered it was realistic to expect that the plaintiff would have needed to reduce his working hours to a half time basis between the ages of 55 - 60.

182 Dr Fong considered that the plaintiff's physical condition and/or his emotional condition would preclude him from a safe return to work on a mine site.

183 Dr Fong said that his assessment of the plaintiff's inability to stand beyond 15 minutes was based on what he had been told by the plaintiff and not as a result of anything that he had observed on examination. He recorded that the plaintiff's neurological examination did not detect any signs of nerve root impingement or any abnormalities affecting his lower limb power, sensation, reflexes or coordination. A peripheral neuropathy condition was tested for and found to be absent.

184 In cross-examination Dr Fong accepted that essentially he could not find any cause for the plaintiff's complaint of leg pain. Dr Fong agreed that upon physical examination the plaintiff was entirely normal and that his opinion as to the disability allegedly suffered by the plaintiff depended upon the plaintiff's comments.

185 He considered that as Mr Smith's pain had endured for some four years since the onset of his injuries it would be unlikely that it would significantly improve or resolve over further time.

187 From approximately late December 2005 to June 2007 the plaintiff consulted Dr Green in relation to, inter alia, the management of his right calf injury. In addition to referring the plaintiff to specialists for advice from time to time, Dr Green issued a number of progress medical certificates that were tendered by consent as part of the plaintiff's case (exhibits 4.1 to 4.63). Dr Green's practice notes were tendered by consent (exhibit 5).

188 As noted earlier in these reasons, the plaintiff obtained leave to re-open his case and called Dr Green to explain why there were seemingly two progress medical certificates in respect of examination of the plaintiff on 25 January 2007 (exhibits 4.32 and 4.33) - one that certified the plaintiff as fit and the other as unfit. Dr Green was also examined as to the circumstances in which the progress medical certificate dated 7 February 2007 (exhibit 4.33) was issued by him with reference to his practice notes of that consultation (exhibit 5).

189 It was Dr Green's evidence that on 25 January 2007 he examined the plaintiff and certified him as fit for his pre-injury duties subject to the rider that the plaintiff 'may need to rest if leg swells' (exhibit 4.32). Dr Green recorded his clinical findings as follows:

Probable compartment syndrome of the right calf. Previous diagnosis of neuritis. Has had pressure test, MRI scan, awaiting outcome.

190 Whilst the next sequential progress certificate (exhibit 4.33) recorded the same date for the examination of the plaintiff to that shown in exhibit 4.32, Dr Green, aided by his clinical notes (exhibit 5.7 at page 12) confirmed that he had in fact examined the plaintiff on 7 February 2007 and that the date on top of exhibit 4.33 was incorrect.

191 I note in passing that the date of injury on this (and several other certificates) was seemingly also erroneously recorded as 15 December 2005, being the date that the plaintiff's calf injury was first recorded by Dr Ittermann rather than the date of the incident.

192 On 7 February Dr Green certified the plaintiff as totally unfit for 28 days.

193 Dr Green's notes for the attendance on 7 February (exhibit G7) are as follows:

Still has discomfort in R calf, it as before, especially with activity.

Results of pressure test available, report by Dr Williams brought in, and give his opinion that there is localised compartment syndrome.

Says employer has paid out with a redundancy. Advise this wouldn't necessarily mean that the case is closed. Needs to work through his lawyer. Says he has been paying all the medical bills that should be paid by the employer.

Has WorkCover conference on 14th February, see after.

On this certificate requested that be made unfit, particularly as Dr Williams wrote that the (sic) needs 6 months of physio etc, before considering case closure.

194 Dr Green said the certificate was based upon the plaintiff's request and a combination of the clinical evidence together with the information in the report of Dr Williams stating that there was a localised compartment syndrome and that the plaintiff would need six months' treatment for recovery - that is to say, that the contents of Dr Williams' report was a factor he considered.

195 When cross-examined by Mr Clyne, counsel for the defendant, Dr Green acknowledged that the plaintiff gave him a copy of a letter from Dr Williams addressed to the plaintiff's solicitors when he presented for examination and requested that he be certified unfit for work.

196 Dr Green acknowledged that the treatment recommended by Dr Williams of physiotherapy, stretching and strengthening exercises was fairly modest but noted that it was over a considerable period of time.

197 Dr Green further accepted that whilst Dr Williams had recommended that the plaintiff receive physiotherapy by way of treatment, there had been no change in the plaintiff's physical state or capacity from when he had previously certified the plaintiff as being fit for his pre-incident employment on 25 January 2007.

198 Dr Green's evidence when cross examined in relation to this aspect was as follows:

CLYNE, MR: And the doctor indicated already that the treatment recommendations he was referring to are the third passage - third paragraph from the bottom. And consisted, Doctor, do you now - of swimming, stretching and some strengthening exercises: Some local physio and stretching and strengthening exercises would be appropriate, with local therapy aimed at resolving the residual irritability - in the calf---Yes.

So it was fairly modest treatment that he required---But over a considerable period of time.

Yes. But in terms of certification for employment, would you not have - reading that advice and looking at what you'd said on 25 January when you certified him fit - would you not have certified him fit for duties still, if he only needed some physiotherapy---Well, on the certification of 25 January I had made a comment that he may need to rest if the leg swells, and often a person would be put on restricted duties, particularly on a mine site, if they did need to rest to give them that opportunity. Because often the employer would say that they should be completely fit to do their normal work.

Yes. But he still had a - a capacity to work as at 7 February, didn't he---Yes, I would have - on - if - if he was employed it would be as partially unfit.

Well, why then the certification of unfitness---He was put unfit because he said he'd been paid out by his employer and - and he would still need the treatment.

Sorry, I don't quite follow that. If you're certifying his physical capacity, is it the case here that, essentially, you made him unfit because he asked you to---He asked me to, but I also took into account this other report.

Yes. That - that's Dr Williams, you mean---Yes.

CLYNE, MR: Because in real terms your clinical examination on those two days is very much the same, isn't it? On 25 January he still had discomfort in his right calf and if you look at your certificate of that date - sorry: Probable compartment syndrome, right calf - left - right calf. Is that right---On the 25th, yes.

Yes. So you had suspected on that occasion exactly what Dr Williams put in his report. Is that correct ---Yes. And it hadn't been confirmed, yes.

Yes. But that's what you thought it probably was on 25 January when you certified him as fit to return to pre-injury duties but requiring further treatment---Yes. But with additional comment of:

CLYNE, MR: May need to rest if the leg swells.

Yes. And in real terms, on your clinical examination on 7 February, his position was exactly the same, wasn't it---Yes, he had discomfort in the calf as before, especially with activity.

And the letter from Dr Williams simply confirmed the compartmental syndrome and that he needed some physiotherapy---Yes.

Yes. So on 7 February, he told you he'd been made redundant, correct---Yes.

What role did that have in you providing this certification of unfitness---It - it has the role that he was no longer - no longer employed.

But he remained the same physically, didn't he---Yes.

Again, why then did you change your certification---The - the patient had requested it and I agreed that as he needed the six months of treatment, that I would write him unfit for that month. (ts720 - 721)

199 I observe that, given that the treatment recommended was minimal and the plaintiff's physical condition was unchanged from the earlier examination, Dr Green's certification of the plaintiff's unfitness to work on 7 February 2007 was seemingly premised on the plaintiff having been made redundant and upon his request rather than on any clinical assessment or changed physical state.

200 I was concerned by such conduct - particularly in circumstances where the certificate is relied on by others to enable the plaintiff to continue to receive payments of wages by way of workers' compensation.

201 I further formed the view that Dr Green was seemingly partisan to the plaintiff's case - a view that finds some support in the somewhat tendentious observation in the final paragraph of Dr Green's letter to MacMahon dated 15 November 2006 (exhibit 5.3).

202 In the circumstances I place little weight on any medical opinion or evidence that Dr Green expressed unless corroborated by other independent evidence that I accept.

203 Mr Lennox Terry is the proprietor of Dynamic Earthmoving ('Dynamic'). Mr Terry said that Dynamic was contracted by MacMahon during the period from 2004 to 2006 to construct and maintain the haulage roads and including, inter alia, the signage on the mine site.

204 Mr Terry said intersection W19 was constructed of Haulpak tyres stacked two high as it was at the crest of a hill. He said that it was constructed of waste material and that soil that was placed inside the Haulpak tyres in which the signs were erected was waste soil that included some rocks but generally was relatively fine gravelly soil. Mr Terry said that the soil used at W19 was similar to that depicted in exhibit A8 at pages 140, 141, 143 and 145.

205 Mr Terry said that the windrows were constructed by tyres being put into position by a front end loader and then soil loaded into the centre of the tyre. A jarrah stake was then driven in and a 2 inch pipe placed over the top of it and hammered in with a sledgehammer so that it would not move. The signs were placed in the centre of the tyres.

206 Mr Terry said that the soil in the tyres was not compacted but when the picket was driven in it was compacted in the area to make sure the post would stand up. He said that the maximum depth that the soil in the tyres would compress may be to a depth of 50 mm but generally would not exceed a depth of about 25 mm. I understood him to be then referring to the time when the intersection was first constructed and the sign erected rather than after it has been in place and subject to weathering for over at least a year if not longer.

207 Mr Terry rejected the suggestion that the type of soil used in the Haulpak tyre at W19 intersection was 'bulldust' or that bulldust had ever been used. He said that it would not have been possible to pick up such fine soil with a loader bucket and that in any event the sign would not stand up in it.

208 Mr Terry said that his contract with MacMahon required him to clean and maintain the signs and the roadside delineators. He said that the signage that was fixed in the tyres was cleaned using a squeeze mop similar to that used to clean car windscreens mounted on a 4 foot pole. He said the mop would be dipped in a bucket and the sign washed whilst standing on the ground.

209 Mr Terry said during the time that he was on the mine site he had seen other people clean the road side delineators but was unaware of anyone cleaning the signs fixed in the tyres other than him.

210 Mr Terry said that whilst he was engaged by MacMahon at the mine site he was aware that Mr Tim Jess would drive around and inspect the site on behalf of the defendant. He confirmed that on one occasion he had been reprimanded by Mr Jess for failing to comply with a safety requirement in not properly tagging off a vehicle when it had run out of fuel. He said the defendant's safety procedures on the mine site required him to tag the vehicle so that it could not be used.

211 Mr Terry was a frank and forthright witness whose evidence is consistent with the probabilities. I accept it as a truthful and accurate account.

212 I further accept that the system used by him for the cleaning of the signs was in place from the outset of his engagement and, particularly, prior to the incident.

213 Mr Garnett was employed by the defendant to oversee the MacMahon mining operations at Mount Whaleback from a safety, environmental and production viewpoint from early 2005 until the end of the mine operations contract in 2007.

214 As part of his duty to ensure site safety he did daily drive-arounds and audited the site from a safety perspective. Mr Garnett said that the defendant required MacMahon to have safety procedures approved by the defendant in respect of all activities and operations on the site.

215 Mr Garnett said that as part of his task he would inspect the roadworks, intersections and signage.

216 Mr Garnett said at times he had noticed safety breaches by MacMahon. On those occasions, if it was serious matter he would stand the operation down immediately, call management and the safety inspectors and stop the operation until it was corrected. He said that MacMahon also employed safety personnel.

217 Mr Garnett was familiar with the intersection W19 and was aware that the construction and maintenance of the intersection including the road-signage had been subcontracted to Dynamic and that Mr Terry was responsible for cleaning the signs.

218 Mr Garnett said he had seen persons cleaning the road side delineators in the past but that he had never seen any people cleaning the signs in the tyres. He said that had he seen anyone stand on the tyres to clean them he would have stopped them as he considered that to work from the height approximately 1.4 m high would be unsafe. In his view anyone cleaning the sign in that way would be foolish and such conduct would not have been tolerated by him.

219 Mr Garnett rejected the suggestion that the soil inside the tyres at W19 into which the signs were fixed comprised bulldust or loose fine soil.

220 Mr Garnett was very experienced mine supervisor who gave his evidence in a frank and forthright manner. I find that he was a credible witness whose evidence was reliable.

221 Mr Martin Durkin was the project manager for MacMahon at Mount Whaleback from December 2004 until mid-November 2005.

222 MacMahon was required to submit a safety management plan to the defendant as part of its tender. Mr Durkin said that during the time that he was at the site, the safety management plans were implemented and thereafter checked daily. In addition to daily checks carried out by the supervisors, the defendant had a system which included going around the mine site and checking to ensure that all safety procedures were being followed within the mining area.

223 Mr Durkin was familiar with the intersection at W19. He said that MacMahon had engaged a subcontractor, Mr Len Terry and Dynamic to construct and maintain the roads and intersections. Mr Durkin said that Dynamic were responsible for cleaning of the signs at the mine site pursuant to their subcontract agreement with MacMahon.

224 Mr Durkin rejected the suggestion that the tyres at the intersection of W19 could have been filled with a fine bulldust-like material. He said that the soil inside the tyres was gravel similar to seen on the side of the haul road or the shoulders of the road - like pea gravel ranging from very small to not too big as it had to fit into the tyre to hold up the sign and stabilise the tyres. Mr Durkin agreed that the soil type shown in exhibit A8 at pages 145 and 146 was representative of that in the tyres at W19. He said that when it rained the soil in the tyres would settle and may be topped up if required.

225 Mr Durkin said that as part of the safety procedures implemented by MacMahon on the site, all MacMahon employees were required to do a 'Take 5' before undertaking any task that was not covered by a designated safety procedure. This system was initiated by the defendant and required employees to stand back from the task to be undertaken and identify any hazards that may be involved and thereafter put steps in place to ensure that the task could be safely performed. It involved a job hazard analysis.

226 Whilst Mr Durkin was not engaged on the site at the time of the incident, I accept his evidence as to the conditions that prevailed generally on the site and at intersection W19 in particular. There was no suggestion that the state of the intersection was changed or altered in the interval between his departure and the incident. I consider Mr Durkin's evidence to be accurate and reliable and in accordance with the probabilities.

227 Mr Philip Hardcastle, a consultant orthopaedic surgeon, reviewed the plaintiff for the purposes of assessing his injury and disabilities at the request of the defendant's solicitors in September 2009.

228 At that time the plaintiff reported ongoing neck and low back pain of equal intensity together with hearing and eye problems. The plaintiff said his right calf pain was continuing and dependent on activity.

229 On examination Mr Hardcastle was unable to elicit any calf tenderness despite being shown the area where it was and where it was generally associated with swelling. Mr Hardcastle noted that the MRI of the plaintiff's calf conducted on 19 January 2007 recorded a small amount of oedema in the anteriormedial aspect of the upper right soleus muscle and which could relate to a low grade strain of the muscle and adjacent myofascial structures but no MRI evidence of compartment syndrome. Mr Hardcastle accepted however that the MRI could not exclude such diagnosis. He further noted the compartmental pressures as tested by Dr Taylor at the request of Mr Williams.

230 Mr Hardcastle opined that the pain in a calf musculature could either be due to local scarring or possibly a form of atypical compartment syndrome when the results of Dr Taylor's compartment pressures were taken into account but balanced with the MRI. Mr Hardcastle suggested that a localised decompression of the compartment could be considered but accepted that this was not his area of expertise and that the plaintiff should be referred to another specialist to advise in respect of that aspect.

231 Mr Hardcastle considered that the plaintiff had a current work capacity as a truck driver from a physical aspect but would need to be reviewed and taken off his medication for the depression that had developed subsequent to his injury. He considered that a return to work may well relieve the plaintiff's depression.

232 Mr Hardcastle did not consider that the plaintiff had a significant restriction given that the plaintiff was able to remain fairly active doing painting, restoration work on motor vehicles, etc. He said that any restriction on lifting weights was due not only to his leg but also his other medical problems. Mr Hardcastle said that, in his opinion, the plaintiff was capable of return to full time employment if his calf was treated.

233 Dr Home is an occupational physician. He examined the plaintiff at the request of the defendant's insurers and his reports tendered (exhibits G1 to G5).

234 Dr Home said that for the purpose of examination, he asked the plaintiff to undress and inspected both legs standing - looking for visible abnormalities. He then asked the plaintiff to walk back and forward, crouch, walk on toes and walk on his heels. He then palpated the plaintiff's joints above and below the calf and palpated the calf to find any areas of tenderness and to determine if there was any induration or hardness. Dr Home then examined the plaintiff neurologically and vascularly and measured his calves and thighs. Dr Home said that the plaintiff gave a history of pain related to driving but not walking.

235 Dr Home noted that upon examination the plaintiff was able to walk on his toes and to repeatedly rise onto his toes performing calf raises without any evidence of swelling or induration in the calf.

236 Dr Home considered the history given to him by the plaintiff of pain from static pressure on the calf and pain caused by driving but absence whilst walking was inconsistent with a diagnosis of compartment syndrome. In his opinion, the most common symptom for compartment syndrome was activity related pain such that, with activity, blood flows into the muscle resulting in tightness in the muscle.

237 Dr Home said that upon examination of the plaintiff he was unable to find any objective evidence of induration, that is to say, hardness in the muscle which would be expected if there had been bleeding in the muscle. Dr Home considered that the objective clinical examination of the plaintiff revealed no sign of any ongoing functional disability and that the plaintiff was fit to resume his pre-accident duties as a truck driver.

238 Dr Home considered that the plaintiff was also fit to undertake alternate full time work as a yard man or a mechanic to a trucking company.

239 Dr Home reviewed the plaintiff in January 2008. At that time the plaintiff told Dr Home that he had been instructed by his doctor to lift no more than 10 kg due to neck complaints and that he was undertaking light duties including sweeping, light gardening, weeding, pruning. On examination Dr Home considered there was no objective basis to restrict the plaintiff from working. The plaintiff confirmed that he was able to drive his motor vehicle but had not attempted any trips greater than one hour. Based on the plaintiff's reported level of activity, Dr Home considered the plaintiff was fit to undertake work as a domestic truck driver transporting palletised or bulk goods.

240 Dr Home reviewed the plaintiff in August 2010. Dr Home noted that upon examination the calves were symmetrical although there was some local tenderness identified by the plaintiff overlaying the medial aspect of the gastrocnemius in the proximal right calf there was no evidence of any abnormality.

241 The plaintiff told Dr Home that he continued to suffer intolerance to prolonged loading on the calf such as prolonged static standing with symptoms of mild discomfort associated with standing for up to three hours.

242 Dr Home considered that the plaintiff may experience exacerbation of his pain if he was to resume his pre-accident employment as a truck driver driving dump trucks on a full time basis but felt that the plaintiff was capable of undertaking tasks such as local truck driving and transporting palletised or bulk goods on short trips. Dr Home qualified such opinion however as being based upon the plaintiff's subjective complaints that he experienced pain associated with driving for three hours. Dr Home noted however that such capacity had not been tested.

243 Dr Home said that upon examination of the plaintiff there was no objective abnormality. In his opinion a single pressure test was not a sufficient basis to make a diagnosis of compartment syndrome. He said that it was necessary to look at all the clinical symptoms and signs to determine if such diagnosis could be supported. Dr Home noted that save for the single elevated pressure tests in late 2006 the plaintiff did not exhibit any other features of compartment syndrome.

244 Dr Home said it was a very unusual diagnosis to be identified in a man who can walk moderate distances without pain. In his opinion those persons with compartment syndrome or post-compartment syndrome problems, the issue was generally an inability to walk beyond a very short distance. In his opinion, with a person suffering a compartment syndrome that is active and causing symptoms, clinical examination will reveal a feeling of tightness in the compartment from the build up of pressure or some evidence other than just local pain.

245 Dr Home considered that it was unusual however to only cause an isolated nerve injury within one little muscle without having any features of problems distal to that.

246 Notwithstanding thoroughly examining the plaintiff, Dr Home was unable to detect any abnormality. Accordingly, Dr Home relied upon the plaintiff's subjective complaints for the purpose of his assessment as to the plaintiff's capacity.

247 Dr Home impressed as being thorough and cautious in his opinion as to the extent of any disability or restriction noted upon his examinations of the plaintiff. Dr Home's opinion as to the plaintiff's restriction is seemingly premised upon his clinical observations and findings and not the plaintiff's account of the incident and the mechanics of the injury. To that extent I find them persuasive and accept his evidence.

248 Dr Cheng, a consultant psychiatrist examined the plaintiff on 22 October 2009 and 19 August 2010 and his reports tendered as exhibits F1 and F2.

249 Dr Cheng considered that the plaintiff did not suffer a psychological disorder as a result of the incident. It was Dr Cheng's opinion that the plaintiff did not suffer from a major depressive episode but rather an adjustment disorder with depressed mood. Dr Cheng considered that the major limiting factors to the plaintiff's level of function appeared to be resulting from his physical symptoms rather than his psychological symptoms. Dr Cheng noted that the plaintiff described significant distress arising from various stressors including his complaints of pain and restrictions on activity as a result of his physical symptoms, the uncertainty surrounding the outcome of his claim, the uncertainty surrounding his future work prospects and his financial situation. Dr Cheng considered any psychological disorder suffered by the plaintiff as secondary phenomena.

250 Dr Cheng said that from a psychiatric point of view there was no restriction on the plaintiff's ability to work. Dr Cheng further considered the medications taken by the plaintiff did not impact upon his capacity to be engaged in his pre-accident employment.

251 Dr Cheng reviewed the plaintiff on 19 August 2010. Dr Cheng considered that the plaintiff was then continuing to suffer from an adjustment disorder with depressed mood. In his opinion, the plaintiff's psychological symptoms were relatively mild and on the borderline of being normal when regard was had as to the plaintiff's then current situation and stressors. Dr Cheng considered that the plaintiff's psychological symptoms had not resulted in a significant impairment in his occupational, recreation or domestic functioning. In his opinion, the plaintiff was fit for his pre-accident employment as a truck driver.

252 In Dr Cheng's opinion any limitations in the plaintiff's functioning related to physical symptoms and in particular, the fact that he was not employed and not in any return-to-work program.

253 In cross-examination Dr Cheng said that when one had regard to the fact that the plaintiff had returned to work after the injury in determining what caused the plaintiff to become more depressed and stressed he noted that the plaintiff's mood became worse since he had been made redundant. Dr Cheng said:

It appears that prior to being made redundant from the work, he was having these symptoms, but he was coping quite well. There's not a sense there that he had suicidal ideation, or didn't report that he had suicidal ideation or things. So he still had the injury, he still had the thing, but it's not until his redundancy and then - so his other concerns about going back to work and then find that then his mood deteriorates. So you get a sense that it's the various stresses and things that he's facing that then alters how much distress and things he's under (ts 320).

254 Dr Cheng opined that if the plaintiff returned to work through a rehabilitation program or found suitable work any distress then suffered by the plaintiff would reduce.

255 Dr Cheng did not then have the benefit of Dr Green's testimony and the plaintiff's further cross-examination as to the circumstances leading to the plaintiff being certified unfit on 7 February 2007 when he expressed his opinion on this matter.

256 I consider that the plaintiff's conduct immediately following his redundancy, including his request for his certification of fitness for work to be changed - seemingly in an attempt to prolong an entitlement to workers' compensation - together with his subsequent action against MacMahon for wrongful dismissal, lends weight to Dr Cheng's assessment that the plaintiff suffers an adjustment disorder.

257 In such circumstances it is more probable that plaintiff suffers from an adjustment disorder and would be assisted by re-engaging in full time employment.

258 Professor Charles Mulvey, the managing director of LabourNet Australia Pty Ltd prepared labour market reports in respect of several occupations for the four year period prior to trial. His reports were tendered by consent (exhibit 6.10 and exhibit A9).

259 In respect of each nominated occupation, Professor Mulvey's report detailed the job classification and requirements, the applicable rates of pay - by award and referenced to average weekly earnings - and the employment availability for a range of occupations that were considered to be within the work capability and capacity of the plaintiff. Such occupations included dump truck/Haulpak driver, diesel mechanic, tip truck driver, domestic truck driver, courier driver, security officer and yardman.

260 It was the defendant's submission that the plaintiff had the capacity to undertake each of the occupations identified in the reports - notwithstanding the degree of the disability of which the plaintiff complains.

261 I refer to the specific observations as to the credibility and reliability of the principal witnesses made in the course of reviewing their evidence. I do not accept the plaintiff as a reliable and accurate witness and prefer the evidence of Mr Lennox Terry, Mr Timothy Jess, Mr Martin Durkin and Mr Ian Garnett where they conflict with the plaintiff on any issue. They each gave clear forthright evidence that accord with the probabilities.

262 Turning to the issues arising on the pleadings I make the following findings:

263 The plaintiff's claim is in respect of the defendant's alleged breach of the duty owed to the plaintiff at common law and pursuant to the provisions of s 13 and s 15A of the Act. Whether the defendant owes a duty to the plaintiff and if so, the nature of such duty calls for consideration of the defendant's activities on the mine site and whether it has retained control and occupation of the site and in turn, the relationship between the defendant and MacMahon as set out in the mine operations contract (exhibit E).

264 The recitals to the mine operations contract include:

1. The contractor (MacMahon) has represented to the company(the defendant) that it has special knowledge in the extraction of iron ore, including drill and blast, stockpiling and the waste dump construction and associated management services, together with demobilisation and associated obligations;
2. The contract has also represented to the company that it is able to carry out and complete the mining activities of the highest regard for safety;

1. The company in reliance on the representations contained in recitals A and B hereof has requested the contractor to carry out and complete the mining activities;

1. The contractor has undertaken to carry out and complete the mining activities in accordance with the terms and conditions of the contract.

265 Pursuant to cl 2.3 of the mine operations contract the defendant was required to prepare a health, safety and management plan in accordance with the defendant's policies and submit it to the defendant for approval. The safety management plan was required to detail the safety system that would be introduced in relation to the performance of work and contain procedures to ensure that MacMahon complied with the Act in relation to issues of health and safety (cl 2.4(c)). Relevantly it was to include, inter alia, details of appropriate requirements for the location, use and maintenance of traffic control signs and devices (cl 2.4(h)(vi)) and plans for traffic management at the site (cl 2.4(h)(ix)).

266 Pursuant to cl 5.2.5 of the Traffic Management Plan (exhibit A4, pages 71 and 72) MacMahon was required to ensure that all reflectors, flashing light and signs were kept clean and in effective working order.

267 By cl 2.10 of the mine operations contract the defendant was permitted to conduct audits of MacMahon's compliance with its safety management plan and its occupational health and safety obligations under the contract and the Act.

268 If during an audit or inspection, non-compliance with any of its obligations (including matters relating to occupational health and safety) were identified, the defendant could issue MacMahon with a corrective action order to remedy the non-compliance within a specified time (cl 2.12). The defendant retained the power to suspend operations in the event of any breach or non-compliance with the Act.

269 I accept that the defendant engaged MacMahon as a qualified mining company to undertake the works the subject of the contract. Part of the work included the construction and maintenance of the haul roads including the W19 intersection. I further accept that the defendant relied upon MacMahon's expertise in carrying out the mining operations.

270 Having regard to the terms of the mine operations contract and the evidence of Mr Timothy Jess, I find that the defendant sought to benefit from the conduct of mining operations at the Mount Whaleback mine site.

271 Further, I am satisfied that the defendant, as the owner of the mine, retained control of the mining operation and at all material times was a 'principal employer' within the meaning of s4 of the Act.

272 It follows that the defendant owed the plaintiff the duties arising under s 13 and 15A of the Act.

273 Further, by reason of the relationship of proximity between the defendant as the owner of the mine with the retained capacity to control the mine site and the plaintiff as a truck driver on the mine site, I am satisfied that the defendant owed a common law duty to the plaintiff to exercise reasonable care for the plaintiff safety on the mine site.

274 The Act does not place a more onerous burden on a defendant in respect of a plaintiff than at common law: Leighton Contractors Pty Ltd v Fox [2009] HCA 35 [49].

275 The defendant was required, so far as was reasonably practicable, to provide and maintain a working environment in which persons such as the plaintiff were not exposed to hazards and to take reasonable care to avoid a foreseeable risk of injury to the plaintiff.

276 The duty particularised by the plaintiff, whether at common law or under the Act, is to take reasonable care to ensure that the plaintiff was not exposed to hazards whilst on the mine site. Pursuant to s 9 of the Act, at its highest it is akin to that of an employer of the plaintiff with the defendant's mine site being the plaintiff's workplace, but tempered with the qualification that is discharged by doing what is reasonably practicable in the circumstances.

277 In the context of the present case and by reference to the alleged breaches particularised in paragraph 8.1 - 8.5 of the Statement of Claim, such duty is said to encompass:

(a) warning the Plaintiff of the risk of injury arising from climbing onto or into the tyres to access and clean the sign;

(b) supplying the Plaintiff with a long handled broom with a scraper similar to those used to clean windscreens and garages to clean the signs instead of climbing onto or into the tyres;

(c) employing or designing a system of cleaning of the signs by instructing or requiring the Plaintiff to use long handled broom to avoid the necessity to step on or into the tyres to obtain the required height to clean the signs;

(d) ensuring that the soil inside the Haulpak tyres was solid and compacted;

(e) inspecting the condition of the soil inside the Haulpak tyres so as to determine whether or not it was a safe working platform to stand on.

278 Insofar as the defendant had the capacity to direct and exercise control over MacMahon in relation to the implementation of procedures relating to health and safety, the defendant's duty extended to matters relating to the establishment of systems by MacMahon as an employer in respect of its employees working on the mine site.

279 I accept that such duty necessarily extended to matters arising under the Traffic Management Plan, including the method of cleaning the signs at W19.

280 I observe however that, to the extent that the duty is said to require the defendant to warn the plaintiff of risk of injury from climbing onto the tyres, there was no duty to warn of obvious risks.

281 The circumstances of the incident are pleaded in par 7 of the statement of claim. The factual issues for determination include:

1. Was the plaintiff required to clean the signs at W19 on 6 December 2005? Alternatively, was it reasonably foreseeable that the plaintiff would clean the signs?
2. Was the soil in the tyres soft, powdery 'bulldust' like soil as described by the plaintiff or firm gravelly soil as maintained by the defendant?
3. Did the plaintiff's leg sinking into the soil in the tyre and cause the plaintiff to fall to the ground?

282 On the morning of 6 December 2005, the plaintiff decided to clean the signs at the W19 intersection.

283 The plaintiff said the signs had been erected in the tyres at the W19 intersection prior to him commencing work with MacMahon at the site in March 2005.

284 The plaintiff said that no one instructed him to clean the signs or to do any other task that morning and he was acting on his own volition and initiative. He said he had been requested to clean the signs by his employer, MacMahon, on a previous occasion. The plaintiff said that he had never seen anyone else cleaning the signs whilst standing on the tyres and that it was his decision to clean them in that way.

285 Mr Kenneth Lee gave evidence for the plaintiff. He said that the plaintiff had been instructed to clean signs by the MacMahon supervisor, Mr Seymour, that morning. As observed earlier in these reasons, I do not find Mr Lee's evidence on this issue reliable.

286 Mr Lennox Terry said that one of the tasks that Dynamic had been engaged by MacMahon to do in relation to road maintenance, was, inter alia to ensure that the signs were cleaned and maintained.

287 I find that the plaintiff had not been assigned the task of cleaning the sign that morning and that at the time he was acting on his own volition and initiative. Further, if the plaintiff cleaned the signs on any prior occasion, I am not satisfied on the evidence that the plaintiff was ever requested or required to do so.

288 I consider that it is improbable that MacMahon would have assigned one of its truck drivers the task of cleaning the signs at W19 intersection when it had engaged Dynamic as the subcontractor to undertake, inter alia, that very task. I do not accept the plaintiff's evidence in this regard.

289 Further, if the plaintiff did clean the signs on a prior occasion, I find that the defendant was unaware that the plaintiff (or any other MacMahon employee) had done so.

290 I accept the evidence of Mr Garnett and Mr Jess that the defendant was aware that Dynamic has been engaged as a subcontractor by MacMahon and that Dynamic was responsible for cleaning the signs. Mr Garnett said that if he had seen anyone cleaning the signs whilst standing on the tyres he would have stopped it. Neither of Mr Garnett or Mr Jess had seen anyone cleaning the signs in the past. Implicit from such evidence is that the defendant was not aware and could not reasonably have anticipated that the plaintiff or any person other than Mr Terry and Dynamic staff would clean the signs.

291 The composition and compaction of the soil in the fourth tyre stack at W19 is fundamental to acceptance of the plaintiff's account as to the circumstances of his fall and the incident generally.

292 The plaintiff says that the signs were in place in the tyres at W19 prior to him commencing work on the site with MacMahon in March 2005.

293 The plaintiff described the soil in the tyres for the first three signs cleaned by him that day as firm underfoot and well compacted. He said that the soil in each set of tyres appeared the same.

294 In relation to the incident, the plaintiff said that as he placed his full weight on the soil in the fourth set of tyres, the soil did not support his weight. He described the soil being of a soft powdery 'bulldust' consistency such that his right leg sank into soil in the centre of the tyre up to his crotch - to a depth he estimated to be approximately 3 feet or slightly less than a metre. The plaintiff said that as he tried to extract his leg, he fell backwards - falling from the top tyre of the stack onto the ground below - striking his head on the ground and his right knee on a rock.

295 Mr Timothy Jess, Mr Ian Garnett, Mr Lennox Terry and Mr Martin Durkin were each familiar with the intersection W19 and gave evidence as to the composition and consistency of the soil in the tyres. Each rejected any suggestion that the soil placed in the tyres into which the sign had been fixed was very fine particled earth or 'bulldust'. They each likened the soil to that depicted in the photographs in exhibit A8 at page 145 - a fine gravelly soil.

296 Mr Jess and Mr Garnett said that if talc-like material such as bulldust was used inside the tyre in lieu of competent soil the sign would have blown over by the first gust of wind.

297 Mr Martin Durkin described the soil as pea gravel similar to that seen on the side of the haul road or the shoulders of the road - ranging from very small to slightly larger as it had to fit into the tyre to hold up the sign and stabilise the tyres. Mr Durkin said that if the soil in the tyres settled following rain it would be topped up.

298 Mr Lennox Terry was involved when Dynamic constructed intersection W19 in 2003. He said the signs were attached to a 2 inch pipe placed over the stake and hammered into the soil with a sledgehammer so that it could not move.

299 Mr Terry said that the soil in the tyres was not compacted (mechanically) but when the stake and pipe was driven in, the soil was sufficiently compacted to ensure that the post and sign would remain erect. Mr Terry considered that when constructed, the maximum depth that the soil in the tyres would compress was possibly to a depth of 50 mm but generally would not exceed a depth of about 25 mm.

300 Mr Terry said that it would not have been possible to pick that up such fine soil with a loader bucket. Further, if such soil type was used, it would not be sufficient to hold the signs erect.

301 In the absence of evidence to the contrary it is reasonable to assume that the signs have been in situ at the intersection since 2003. There was no suggestion in the evidence that the signs at the intersection in December 2005 had been altered either before or after the incident.

302 I accept the evidence of Mr Jess, Mr Durkin, Mr Garnett and Mr Terry as to the composition and compaction of the soil in the tyres at the intersection W19.

303 I find that the soil in the tyres was of a gravelly type soil that was compacted and firm underfoot and the posts to which the signs were attached were rigidly secured in the soil.

304 The tyres abut either end of a windrow of raised loose waste soil - soil that has been pushed into a long narrow heap but maintained at the height of the tyres. The signs are fixed to a stake within the tyres at the end of the windrow. One would reasonably expect that the loose soil in the windrow would be of the same or similar composition to the soil that was placed in the tyre and supporting the sign. Mr Terry's evidence supports that view.

305 Whilst Mr Terry acknowledged the soil may compress approximately 25 cm but I find it wholly improbable that it could be so loose as to allow the plaintiff's booted foot to penetrate to a depth greater than 25 mm if at all.

306 Importantly the signs at W19 had been secured in place for a considerable period of time prior to the incident and washed on previous occasions by Mr Terry. It is wholly improbable that signs that have remained rigidly secured in position for such a lengthy period would have done so if the soil in the tyre was so powdery and soft as the plaintiff contends. It is more probable that the soil would have settled into the tyres over time with the influence of normal environmental conditions, including seasonal rain such that it would become firm and compacted. That the sign post was held rigidly in position supports such view.

307 I do not accept the plaintiff's evidence that the soil was fine talc or of bulldust like consistency such that it did not support his weight and cause him to sink to his crotch in the soil whilst the sign remain rigid and unaffected.

308 If the surface of the soil had been so powdery and loose as the plaintiff contends, it is improbable that the sign that was held imbedded in that soil would have remained rigid.

309 The plaintiff has given various accounts as to the circumstances of the incident. The plaintiff maintains that as he placed his foot on the soil within the tyre his leg sank into the soft bulldust like soil up to his crotch. He says that as he pulled his leg out of the soil, he overbalanced and fell to the ground below, striking his head on the ground and his right knee on a rock.

310 The plaintiff's entire account rests on a finding that the contents of the tyre was bulldust, that is to say soft, loose talc-like soil that was not load bearing as opposed to firm compacted soil. The plaintiff contends that the surface of the soil on the fourth set of tyres appeared to be of the same type and consistency as the previous three stacks.

311 The only first-hand account of the incident is given by the plaintiff.

312 I reject as wholly improbable the plaintiff's account as to the incident and in particular that the plaintiff's leg sunk into fine 'bulldust' or talc-like soil in the tyre to a depth approximating a metre or at all. I do not accept that the incident occurred as the plaintiff has described. It is contrary to the evidence I accept and wholly against the probabilities.

313 Whilst the circumstances of the incident were subsequently recorded in the incident report of the accident, and in the medical reports, those accounts are based entirely upon the plaintiff's version of the events. They provide no independent support of his account. Mindful of critical differences in his description of the incident I do not accept the plaintiff's evidence as truthful and accurate on this issue. As noted earlier, in my opinion the plaintiff could not have honestly believed that the incident occurred in the manner described by him at trial.

314 I do not accept the plaintiff's evidence that the soil in the tyres was 'bulldust' like and further, do not accept the plaintiff's evidence that he sank to his crotch or to any depth whatsoever in the soil as he maintains.

315 I am satisfied on the evidence that the soil in the tyres at intersection W19 on 6 December 2005 was firm underfoot.

316 I accept that the plaintiff fell and struck his knee on the morning of 6 December 2005 however I do not accept that it occurred in the manner contended by him. Further, I am unable to conclude on the evidence on the balance of probabilities as to where, why and how the plaintiff fell and suffered the injury that he now complains of. I am not in a position, in the absence of evidence that I accept, to make any determination as to what happened save that I accept that he did suffer a fall that morning. I am not satisfied however that he fell from the top of tyre stack as he has described.

Is acceptance of plaintiff's account of incident critical?

317 Counsel for the plaintiff, Mr Nugawela referred to Hamilton v Nuroof (WA) Pty Ltd [1956] HCA 42; (1956) 96 CLR 18 and submitted that it was unnecessary to establish the precise mechanics as to how the plaintiff sustained his injury. He submitted that the risk or hazard from which the plaintiff should have been safeguarded was working at a height. That risk did not depend on the constitution of the contents of the tyre. There was relevantly a risk, that is to say, the obvious risk of falling from a height of 5 feet or 6 feet which may occur even through the plaintiff's inadvertence. It was submitted that the incident occurred because the plaintiff was required to work at a height when there was no necessity to do that if a safe system to clean the signs with a long shanked broom or mop was mandated.

318 Hamilton v Nuroof concerned the duty of an employer to adopt a safe system of work. The trial judge was unable to identify precisely how the plaintiff came to receive a splash of bitumen in his eye and onto his face that caused him to drop the bucket of heated bitumen and suffer severe injury.

319 As observed by Dixon CJ and Kitto J (at page 24) it may be unnecessary for a plaintiff to show exactly how an injury occurred if there is a defect in the system of work and it is clear that the injury arose out of that defective system. The act of passing a bucket of hot bitumen above one's head was an unsafe system and obviously so. As a matter of common sense to lift hot bitumen in a bucket raised above ones head for another to accept carried an increased risk of injury compared to other ways of raising the hot bitumen to roof height. There was no question as to the primary facts relating to the system used to lift the bucket of molten bitumen, the trial had focused on what had caused it to splash as it was being passed up by the workman.

320 In Hamilton v Nuroof there was no question as to how or why the plaintiff's suffered injury. Unlike that case, in the present case I am unable to say on the evidence how the plaintiff came to fall, save that I find it did not occur in the manner described by him and, in particular, was unrelated to the nature of the soil in the tyres.

321 Whilst I accept that the plaintiff fell and cut his knee I am not satisfied as to how or from where he fell and suffered the injury. It is for the plaintiff to prove on the balance of probabilities how he came to suffer his injury and identify how it is said to have occurred as a result of the defendant's breach of duty. It is not appropriate that I engage in guesswork or speculation.

322 Having regard to the findings I have made as to the circumstances of the incident I make the following observations in relation to the duties alleged and the defendant's response.

323 The duty cast on the defendant by the Act and at common law was to ensure that MacMahon had established and maintained the workplace, plant and systems of work to properly safeguard persons, such as the plaintiff, from hazards on the mine site.

324 It was not open to the defendant to point to MacMahon and require MacMahon deal with the matter. The defendant retains primary responsibility to ensure the necessary system was in place pursuant to s15A (5) of the Act. That said however, the duty is not one of strict liability. The defendant is required to provide and maintain a working environment in which those deemed to be its employees are not exposed to hazards only so far as is reasonably practicable.

325 As noted earlier in these reasons, this calls for the making of a value judgment in light of all the facts and examined practically but ever mindful of the defendant's responsibility for the safety of those who work or are deemed to work for the defendant.

326 The defendants 'state of knowledge' relating to, inter alia, the risk of injury and the means of removing or mitigating the risk, in determining what is required by way of response is important.

327 Significantly MacMahon's systems including those of their subcontractors were required to address all relevant safety issues to the satisfaction of the defendant. It necessarily follows that any system that was employed or in operation by MacMahon (or any subcontractor) under the direction and supervision of the defendant for the cleaning of signs ought to be treated as if it was the system then in place by the defendant as if it was the plaintiff's employer and the defendant's response to the duty owed to the plaintiff judged accordingly.

328 In my opinion, the duty owed to the plaintiff does not extend to requiring the defendant to establish a duplicate system to those implemented and maintained by MacMahon under the supervision of the defendant. Whilst the defendant remains primarily liable it is reasonable and practical to discharge its duty by requiring that such system provided and maintained by MacMahon and regularly auditing and inspecting the areas of operations at mine site to ensure compliance.

329 All that was required by the defendant to discharge its duty to the plaintiff was to do what was practicable. Accordingly, to the extent to which Dynamic had been engaged to construct and maintain the road works and signs, the system adopted by MacMahon would necessarily be the system in place for the purposes of the defendant in fulfilling its obligations pursuant to s 9 of the Act.

330 It follows that the system used by Dynamic involving the use of a long handled squeeze mop was for the purposes of this case, the system that maintained by the defendant in discharge of any duty owed to the plaintiff.

331 Further, even if the defendant did not specify such system or was not aware of the same, such failure does not give rise to liability in favour of the plaintiff.

332 The plaintiff's claim is in respect of the absence of a system for a volunteer on a frolic of his own. The defendant was aware that Dynamic was engaged to maintain the roads and, inter alia, clean the signs. In the absence of evidence that the defendant was aware or ought to have been aware that persons, such as the plaintiff, might climb onto the tyres to clean the signs in an unsafe manner, nothing was required by the defendant by way of response. It would be neither reasonable nor practical to require the defendant to respond to such risk.

333 Even if the defendant ensured that such system was in place, it would not have safeguarded the plaintiff if, without the knowledge of the defendant (or his employer) he elected to undertake the task of his own volition in a different manner.

334 Further, in my opinion, the defendant mandating that all persons who were to work on the mine site were required to first successfully complete an induction training course on all aspects of mine site safety and hazard risk assessment - including the 'Take 5' program - coupled with regular daily safety inspections by the defendants safety personnel was a reasonable and practical response to any such risk.

335 In respect of the alleged breaches of duty particularised by the plaintiff in respect of his claim both at common law and pursuant to the Act, I make the following observations and findings:

(a) As to the allegation that the defendant failed to warn the plaintiff of the risk of injury arising from climbing onto or into the tyres to access and clean the sign:

336 The plaintiff undertook the task on his own volition without the defendant knowing or being reasonably expected to have known that it may occur.

337 The extent of any duty to warn was limited to those in the class of persons to whom a duty arose. In the context of this case, the class of persons would be restricted to those who might reasonably be expected to undertake the task of cleaning the signs. The defendant's duty did not extend to watching over the plaintiff to ensure that he was not injured whilst on a frolic of his own when the defendant had no notice that he was likely to do so.

338 Further, I am satisfied that any risk of injury from climbing onto the tyres to clean the signs was so obvious that it was not necessary for the defendant to warn the plaintiff of the risk of injury. I will return to this aspect later in these reasons.

339 I find that the surface of the soil was compact and firm and did not pose any hidden danger or risk to the plaintiff that was not otherwise obvious namely, any risk that might be associated with standing upon a tyre filled with soil 5 feet from the ground.

340 The claim under this particular is not made out. The plaintiff was not exposed to any hazard by the defendant.

(b) As to the allegation that the defendant failed to supply the plaintiff with a long handled broom with a scraper similar to those used to clean windscreens and garages to clean the signs instead of climbing onto or into the tyres.

341 I accept the evidence of Mr Terry that the system then utilised by those persons engaged to undertake the task of cleaning the signs required the use of a long handled squeeze mop from ground level and that those persons charged with the responsibility to undertake the task did so.

342 There was no requirement for the defendant to supply the plaintiff with such equipment insofar as the plaintiff was neither requested nor required to undertake that task. There was no reason for the defendant to expect that a truck driver employed by MacMahon would seek to do the work of others in an unsafe manner in such circumstances.

(c) As to the allegation that the defendant failed to employ or design a system of cleaning of the signs by instructing or requiring the plaintiff to use long shanked brooms to avoid the necessity to step on or into the tyres to obtain the required height to clean the signs.

343 It is the plaintiff's case that the defendant should have provided instruction, training and supervision of the plaintiff to enable him to perform his work so that he was not exposed to hazards. This was said to require the use of long handled brooms or brush to clean the sign without the necessity of the plaintiff climbing onto the tyre stack.

344 At the time of his injury the plaintiff was not undertaking a task that had been allocated to him either by his employer or anyone else. The task of cleaning and maintaining the signs was allocated to Dynamic. As the plaintiff concedes, he took it upon himself to clean the signs and was not instructed to do so.

345 The defendant had the capacity to supervise the work undertaken by MacMahon to ensure that the systems employed were safe for use by its employees - including requiring that all personnel successfully completed safety induction training before commencement. Further, the defendant maintained regular site inspections and safety audits to ensure that such systems were property employed and safety requirements were observed.

346 As noted above I am satisfied that there was a system in place for the cleaning of the signs and that those persons instructed to do that task used that system.

347 I am satisfied that there was no breach of the duty by the defendant insofar as there was no obligation on the defendant to instruct the plaintiff as to how to undertake a task that he was not requested to do and could not reasonably have been expected to undertake.

348 Whilst the defendant cannot point to MacMahon in defence of the plaintiff's claim, the defendant is entitled to have regard to all of the systems in place. In the absence of evidence that the defendant was aware that the plaintiff would attempt to clean the signs in an unsafe way, no further response from the defendant was required.

349 The defendant's conduct and response to the obligation to ensure that the plaintiff is safeguarded from hazards should not to be considered in a vacuum. Having regard to all of the circumstances, the defendant's response to the requirement to safeguard the plaintiff was reasonable and practical.

(d) As to the allegation that the defendant failed to ensure that the soil inside the Haulpak tyres was solid and compacted.

350 The system employed by the defendant to ensure the safety of those on the mine site included the mandated inspection of all workplaces at the commencement of each shift. The surface of the tyres was not a place of work or a work platform upon which employees were required to undertake their duties.

351 In any event, I find that the soil inside the tyre was solid and compacted. Any failure on the part of the defendant to inspect the surface of the tyre did not cause any loss to the plaintiff.

(e) As to the allegation that the defendant failed to inspect the condition of the soil inside the Haulpak tyres so as to determine whether or not it was a safe working platform to stand on.

352 There is no evidence that the defendant was aware or ought reasonably to have known that persons would stand on the tyres to clean the signs. The defendant was aware Dynamic had been engaged to clean the signs. The system adopted by Dynamic was to use the very system suggested by the plaintiff.

353 There can be no basis to suggest that the defendant should warn all and sundry against risks associated with standing on the tyre to clean the sign in the absence of some factual basis that such warning was or may be required.

354 In any event, the risks associated with standing on the tyre was so obvious that no warning was required.

355 A warning would only be necessary if the hazard arising with the tyres was not obvious. I find that the soil was firm underfoot and did not create a concealed hazard as described by the plaintiff. No warning was necessary.

356 Any failure to inspect the condition of the soil did not give rise to any injury by the plaintiff. Furthermore, the soil filled tyre was not required as a working platform insofar as the signs were cleaned used a long handled squeeze mop from ground level.

357 The defendant audited the systems used by MacMahon and directly inspected each worksite and supervised such systems to ensure compliance with all aspects of safety. Further, MacMahon were required by the defendant to inspect each worksite at the commencement of each shift and address all safety issues.

358 Mr Garnett said that he would not have permitted anyone to clean the signs standing on the tyres at a height of 1.4 m.

359 MacMahon had a system in place that safeguarded their employees, including the plaintiff.

360 If the defendant's representatives had enquired as to the system and equipment used to clean the signs, they would have been advised of the system used by Dynamic - the contractor responsible to MacMahon for cleaning the signs. In the absence of evidence that the defendant was aware or ought to have been aware that someone other than Dynamic would seek to clean the signs or put on notice as to that possibility, it would be unreasonable to require the defendant to ensure that all persons on the site do not clean signs other than by using a long handled broom.

361 It is not reasonably practical to require the defendant to prevent strangers from undertaking such tasks at their own volition. It would in essence require the defendant to engage persons to supervise all persons on site to ensure that they did not undertake tasks not allocated to them on a frolic of their own.

362 I find that to the extent that the defendant owed any duty to the plaintiff as pleaded or at all, the defendant did not breach any such duty.

363 It follows that the plaintiff's claim must be dismissed.

364 Notwithstanding my findings above I now turn to the remaining issues that were live on the pleadings.

365 Section 5F of the CLA provides for an obvious risk as follows:

(1) For the purposes of this Division, an obvious risk to a person who suffers harm is a risk that, in the circumstances, would have been obvious to a reasonable person in the position of that person.

(2) Obvious risks include risks that are patent or a matter of common knowledge.

(3) A risk of something occurring can be an obvious risk even though it has a low probability of occurring.

(4) A risk can be an obvious risk even if the risk (or a condition or circumstance that gives rise to the risk) is not prominent, conspicuous or physically observable.

(1) In determining liability for damages for harm caused by the fault of a person, the person who suffers harm is presumed to have been aware of the risk of harm if it was an obvious risk, unless the person proves on the balance of probabilities that he or she was not aware of the risk.

(2) For the purpose of this section, a person is aware of a risk if the person is aware of the type or kind of risk, even if the person is not aware of the precise nature, extent or manner of occurrence of the risk.

367 Section 5O of the CLA provides, so far as is relevant for this case as follows:

(1) A person (the defendant) does not owe a duty of care to another person (the plaintiff) to warn of an obvious risk to the plaintiff.

368 The extent of the duty owed by the defendant was to safeguard the plaintiff from any unusual hazard.

369 The plaintiff's case is that there was a risk that he may overbalance or lose his footing and fall to the ground from the top of the tyre stack whilst cleaning the signs at a height of 1.4 metres - even if it transpired through the plaintiff's own inadvertence.

370 Counsel for the defendant expressed the risk as plainly obvious - if someone works at such a height, there is always a risk of falling. It is a matter of common sense that if the plaintiff attempted to clean the signs whilst standing on the tyres, there was always such risk.

371 The plaintiff has not proved that he was not aware of this obvious risk. There was no need for the defendant to warn the plaintiff of such obvious risk.

372 The decision of the plaintiff to climb on to the tyres to clean the sign was his alone. It was inherently risky and the defendant acting with reasonable skill and care could not reasonably have been expected the plaintiff to conduct himself in such manner.

373 I am satisfied that the risk associated with standing on tyres approximately 1.4 m high for any purpose was so obvious that the plaintiff required no warning as to such risk. In my opinion the defendant did not owe a duty of care to the plaintiff to warn of that risk.

374 It follows that insofar as the plaintiff's claim relies upon the defendant's failure to warn the plaintiff of such danger, the claim must fail.

375 Further, insofar as the plaintiff alleges that the nature of the soil in the tyre posed an unusual hazard and that the defendant had a duty to warn of that risk, consistent with my findings as to the constitution and compaction of the soil I find that it posed no danger and accordingly no warning was required.

376 If, contrary to my finding, the plaintiff did fall from the top of the stack of tyres when cleaning the sign, it is necessary to consider the issue of contributory negligence. By its defence the defendant alleged that the plaintiff was guilty of contributory negligence in that he:

(a) failed to take adequate precautions for his own safety by doing a 'Take 5' and assessing the risk of proceeding onto the tyre to clean the sign ; and

(b) failed to exercise reasonable care for his own safety.

377 The CLA provides for contributory negligence at s 5K as follows:

(1) The principles that are applicable in determining whether a person is liable for harm caused by the fault of the person also apply in determining whether the person who suffered harm has been contributorily negligent in failing to take precautions against the risk of that harm.

(2) For that purpose -

(a) the standard of care required of the person who suffered harm is that of a reasonable person in the position of that person; and

(b) the matter is to be determined on the basis of what that person knew or ought to have known at the time.

378 The risk of the plaintiff falling if he overbalanced or lost his footing when cleaning the sign whilst standing on the tyre was a foreseeable risk to the plaintiff of which he well knew, or ought to have known. A reasonable person in his position would know, or ought to have known, of that risk.

379 Further, the risk of harm in climbing onto the tyre was not insignificant, but, a real and substantial risk, such that in those circumstances, a reasonable person in the shoes of the plaintiff would not have climbed onto the tyre at all. The probability that harm may occur was such that it should not have been attempted. To fall from that height was likely to result in harm yet the burden of taking precautions was minimal. The need to clean the signs - a task to which others were allocated and when the plaintiff was not required to do so - did not outweigh the risk of harm.

380 If I am wrong as to the circumstances of the plaintiff's fall I find that the harm suffered by him would not have occurred but for the risk taken by the plaintiff.

381 The plaintiff admitted in cross-examination that he did not do a 'Take 5' assessment before proceeding to walk along the windrowed earth and climbed onto the tyre stack.

382 I find that if the plaintiff had carried out such assessment as he had been instructed so to do, any risk of injury from undertaking such task would have been obvious and could have been avoided. In such circumstances it is appropriate to reduce his compensation by reason of it.

383 I am satisfied that contributory negligence has been established against the plaintiff.

384 As observed by the High Court in Podrebersek v Australian Iron & Steel Pty Ltd [1985] HCA 34; (1985) 59 ALJR 492, 497, the following approach should be taken in apportioning responsibility:

The making of an apportionment as between a plaintiff and a defendant of their respective shares in the responsibility for the damage involves a comparison of both culpability, ie of the degree of departure from the standard of care of the reasonable man (Pennington v Norris [1956] HCA 26; (1956) 96 CLR 10 at 16) and of the relative importance of the acts of the parties in causing the damage: Stanley v Gypsum Mines Ltd [1953] UKHL 4; [1953] AC 663 at 682; Smith v McIntyre [1958] TASStRp 11; [1958] Tas SR 36 at 42 - 49 and Broadhurst v Millman [1976] VicRp 15; [1976] VR 208 at 219 and cases there cited. It is the whole conduct of each negligent party in relation to the circumstances of the accident which must be subjected to comparative examination. The significance of the various elements involved in such an examination will vary from case to case; for example, the circumstances of some cases may be such that a comparison of the relative importance of the acts of the parties in causing the damage will be of little, if any, importance.

385 In the light of the findings I have made as to the circumstances of the incident, I find that the plaintiff is responsible to the substantial degree for his injury and must bear the brunt of his loss. I consider a just and equitable apportionment of responsibility between the parties to be reduced by 80% in the event that there was a duty of care by the defendant, that it breached that duty and that such breach was causative of loss and damage.

386 The plaintiff pleads in par 9 of his statement of claim that as a result of the accident he suffered injuries, namely: nervous shock, right knee injury and right calf injury. It is further pleaded (par 12) that as result of the injuries the plaintiff suffered permanent 2% right lower limb impairment and psychiatric illness sounding in a loss of earnings and earning capacity as particularised in par 13 of the statement of claim.

387 I am not in a position, in the absence of evidence that I accept, to make any conclusion as to what happened save that I accept that the plaintiff fell on the morning of 6 December 2005 and thereby injured his knee. I am not satisfied that he fell from the top of tyre stack as he has described. Further, I am not satisfied on the evidence that the plaintiff's calf injury was occasioned by the fall.

388 I am unable to conclude on the evidence from where and how the plaintiff fell or what caused him to be injured that day save that I accept he did fall and cut to his right knee.

389 The plaintiff first described the injury suffered as striking his knee on a rock (exhibit D). His injuries were later recorded by Dr Ittermann as a laceration and swelling to right anterior patella, that is to say, a cut to the front of and swelling to his right knee.

390 The plaintiff subsequently described the incident to Dr Home as a fall whereby he struck the front of his right knee; cutting his knee and suffering abrasions to his nose and chin.

391 Whilst I accept that there is no evidence of any other incident that may have caused the plaintiff to suffer an injury to his calf muscle, I observe that the plaintiff did not immediately report any injury to his calf to Dr Ittermann the next day. It was not until some nine days after the incident that the plaintiff expressed concern about his calf and then in relation to a possible thrombosis.

392 In support of his diagnosis of a compartment syndrome injury Dr Williams places considerable weight upon the traumatic nature of the tearing of the calf muscle - a severe muscle stretch/strain type injury - as a consequence of the mechanism of the plaintiff's fall. Dr Williams expressed the incident as a traction injury to the calf caused by the leg being stuck in the soil when he fell.

393 I note that the dramatic and painful fall such as that described by the plaintiff in his evidence was not reported in such terms to Dr Ittermann the next day. If the plaintiff had suffered an extension muscle strain type injury in the manner as it was described by Dr Williams in his evidence, one would have expected such description to be found in the initial report of the incident. I consider the fact that it was not immediately reported in such terms is remarkable.

394 Save for one pressure test in December 2006 - one year after the incident - and some differences in the measured calf muscle circumference from time to time, there are few symptoms readily discernible in respect of the plaintiff's injury.

395 In his report dated 20 January 2009 (exhibit 8.38) Dr Williams observed that upon clinical examination of the plaintiff minor differences in calf measurements were noted. The measurements taken 10 cm below the patella, showed the diameter of the left gastrocnemius as 42 cm and the right 43 cm. At 15 cm below the patella, the left was measured at 43.9 cm and the right at 44 cm.

396 I note that on 15 December 2005, when the plaintiff first reported his calf pain to Dr Ittermann, the plaintiff's calf diameter measurements were recorded as 46 cm to the right calf and 44.5 cm for the left calf - a difference of 1.5 cm (exhibit 4.5).

397 Clinical examination and other testing including the MRI lend little support for such diagnosis.

398 Having regard to the findings I have made as to the plaintiff's credibility as a witness, his complaint of calf muscle pain should be viewed with considerable caution.

399 Those medical practitioners engaged to review the plaintiff generally have relied on the plaintiff's subjective account of the pain suffered and his restrictions in mobility. To the extent that their observations as to the seeming genuine nature of the plaintiff's complaints were solicited by the plaintiff counsel during their evidence, I note that such observations were made without the benefit of hearing all of the evidence presented in the case and was restricted to those occasions that the plaintiff attended scheduled appointments to be assessed by them in relation to his claim.

400 As Dr Home said, 'It is a most unusual diagnosis'.

401 Notwithstanding the clinical observation as to the differences in the circumference of the calf muscles mentioned above, as noted by Dr Home, there was no noticeable change observed following exertion. Further, the relative differences noted by Dr Williams from those measurements taken in 2006 show a consistent variation. For the relative differences in calf measurements to be meaningful, benchmark pre-incident measurements are required for comparison. Regrettably no such information has been provided.

402 Dr Home and Mr Hardcastle each observed there is an absence of any tightening of the muscle following exercise that might otherwise support a compartment syndrome diagnosis.

403 I am not satisfied on the balance of probabilities that the plaintiff suffers the restriction to his right calf to the extent as he claims.

404 Further, I not satisfied on the evidence that the plaintiff's calf injury occurred as a result of the incident. Whilst it may be open to infer, in the absence of any other explanation, that the plaintiff's calf muscle was injured at the time of his fall on 6 December 2005, the circumstances of the incident and the reported injury as I find them to be do not support such conclusion.

405 Significantly, the mechanics of the fall that are relied on by Dr Williams in respect of his compartment syndrome injury diagnosis are not established by the evidence accepted by me.

406 Absent the description as to the mechanism of the fall, there is seemingly no basis to suggest that the plaintiff's compartment syndrome injury occurred at the time of the incident - save for the reference to the plaintiff being provided with an ice pack.

407 Dr Koh recorded the history provided by the plaintiff in July 2007 as being calf pain that emerged a week later.

408 Further, the calf muscle was seemingly asymptomatic for some nine days after the incident. It was then believed to be a possible thrombosis - rather than the result of a significant muscle strain or similar injury.

409 If the injury suffered by the plaintiff affecting his calf is a compartment syndrome I am not satisfied on the evidence that such injury is causally related to the incident.

410 I accept the observations and opinion of Dr Home as to the plaintiff's injury. Dr Home observed that it is usual with a compartment syndrome injury to expect tightening in the muscle following activity. Dr Home observed that such symptoms were not apparent when the plaintiff engaged in measured activity. In Dr Home's opinion, the complaint of tightness in the muscle following relative inactivity such as driving was inconsistent with such diagnosis.

411 I find Dr Home's explanation more consistent with the evidence that I accept - particularly in relation to the circumstances of the incident.

412 In contrast Dr Williams' opinion is substantially based upon the subjective account of the plaintiff as to the pain suffered and the description of the mechanics of the incident.

413 I prefer the evidence of Dr Home to that of Dr Williams.

414 I am not satisfied that the plaintiff has suffered the loss claimed by reason of his lost capacity to engage in his pre-incident employment. I am satisfied on the evidence that the plaintiff was capable of performing his pre-incident duties as a truck driver up until he was retrenched on 30 January 2007. I am fortified in this view by the extent to which the plaintiff was able to engage in his usual occupation until he was retrenched and then, seemingly without any change in his physical condition was certified by Dr Green wholly unfit for work at his request.

415 Further, even if the plaintiff did suffer any injury to his calf, I find that the injury suffered by the plaintiff was of such a nature that no surgical intervention was required and its treatment required nothing more than light exercise and perhaps some physiotherapy as recommended by Dr Williams in late 2006.

416 The plaintiff did not undertake the course of treatment recommended and proceeded to challenge his retrenchment from MacMahon at a time when he had been falsely certified as unfit to engage in his pre-incident occupation - there having been no alteration to his physical symptoms that warranted such assessment.

417 The plaintiff did not adduce any evidence of having suffered nervous shock as result of the incident and accordingly that aspect of his claim must fail.

418 As to the plaintiff's claim that he has suffered a psychiatric illness as result of the incident I make the following observations and finding:

419 Dr Williams said that the neuropathic pain which subsequently emerged as a more significant problem could have been treated if the plaintiff had had a more active physical rehabilitation with a course of exercise, swimming or stretching together with measured response by Lyrica. In his opinion the plaintiff's injury would have resolved by June 2007. He said that once the plaintiff's pain became chronic, it was a more difficult neuropathic problem to deal with. Dr Williams considered that the denial that the plaintiff's injury by MacMahon's insurers was significant. He considered that the effect of rushing to get the plaintiff back to work with a disregard his symptoms was such that the plaintiff's symptoms became chronic. Dr Williams said that with the chronic nature of his symptoms came the depression where the plaintiff felt he was going in circles and not getting anywhere.

420 Mr Manners has described as to how the plaintiff's symptoms have developed to one of psychiatric illness and not simply an adjustment disorder.

421 Dr Cheng says that the psychological disorder is not a consequence of the injury but rather a factor such as being made redundant.

422 To the extent that the plaintiff subsequently developed any psychiatric disorder, I prefer the evidence of Dr Cheng and find that it is more likely that it was an adjustment disorder consequent upon the plaintiff being retrenched, rather than any significant psychiatric illness. It is more probable that it is an adjustment disorder, given the history of events that followed the plaintiff's redundancy including his request to be declared unfit (seemingly in an attempt to prolong his entitlement to workers' compensation), the challenge to his redundancy and his subsequent exaggeration of the circumstances of the incident generally.

423 I find that the onset of any depressive condition did not result from the injury or a failure to diagnose the injury but rather as an adjustment disorder consequent upon the plaintiff's inability to accept his redundancy.

Evidence of the plaintiff as to extent of injury

424 Notwithstanding the findings I have made as to liability and as the credibility of the plaintiff generally, I am required to proceed with the assessment of the plaintiff's damages lest I have erred in law or fact on issue of liability.

425 I find that the plaintiff was fit to engage in his pre-incident employment up until his retrenchment from MacMahon and thereafter. I do not accept the plaintiff's evidence as to his ongoing symptoms following his redundancy and the extent to which he says they impacted upon him.

426 The plaintiff was certified as wholly unfit for his pre-accident employment by Dr Green on 7 February notwithstanding that there had been no change to the plaintiff's physical state from when he was considered fit on 25 January 2007. The only relevant changed circumstance was the plaintiff's retrenchment by MacMahon on 31 January 2007. The plaintiff challenged his redundancy unsuccessfully and thereafter seemingly focused on his injury - an injury that then only required mild treatment including some physiotherapy and swimming and was not such as to prevent him from engaging in his pre-accident employment.

427 The plaintiff was distressed that he was filmed by the defendant's insurers and that people did not believe him in relation to his injury. Given the extent of activity seemingly able to be undertaken by him this is not surprising.

428 I do not accept that he has an ongoing disability, the responsibility for which should rest at the defendant's door.

429 I am satisfied that the plaintiff was fit to work on 7 February 2007 - save for needing some tablets for any pain that may arise and a mild exercise regime with perhaps some local physiotherapy. I find that there was no material change in his physical health from when the plaintiff was certified fit on 25 January 2007. The only justification for the change in certification was the plaintiff's request consequent upon him being made redundant. The fact that Dr Williams had recommended an exercise program and perhaps some local physiotherapy was not such as to preclude the plaintiff from engaging in his pre-incident employment.

430 Thereafter the plaintiff resisted his redundancy and went down the path of claiming to be incapacitated and pursuing such relief as was available to him against his employer under workers' compensation legislation. The natural response for his employer, MacMahon, was to do all that was necessary to enable the plaintiff to be rehabilitated. This included assisting the plaintiff to obtain trial work through a rehabilitation agency. When the funds were exhausted, the plaintiff was advised that he had no further avenue to pursue against MacMahon.

431 The plaintiff commenced proceedings against the defendant on 5 August 2008.

432 To the extent that the plaintiff was certified unfit to resume his pre-disability activities after February 2007, I placed little weight upon such certificates. The certificates rely principally upon the plaintiff's subjective account as to the extent to which he suffered the disability complained.

433 Dr Williams in his report dated 12 March 2007 then considered that the plaintiff would benefit from a graduated return to work and light sedentary activities, initially up to three days a week, starting half a day and building up to a full day and then increasing from three to five days a working week over a period of six to eight weeks, depending on the plaintiff's response. The plaintiff's return to work would necessarily have to allow for his continued intensive rehabilitation efforts centred around swimming, exercise schedules and stretching programs.

434 When cross-examined, Dr Williams qualified such assessment as simply dealing with the muscle contusion injury - the soft tissue elements of the injury.

435 To the extent that the plaintiff says that he suffered discomfort in his right calf, I note that he has done little if anything by way of rehabilitation as directed. Indeed, when the statutory allowances in respect of his workers' compensation entitlement from his employer MacMahon was exhausted, the plaintiff has done nothing by way of rehabilitation thereafter.

436 To the extent to which the plaintiff's physical condition has deteriorated over the ensuring period, if at all, I consider it to be a consequence of the plaintiff's failure to engage in the exercise regime recommended by Dr Williams in November 2006 and other physical factors unrelated to the incident including diabetes and blood pressure - illnesses for which he has been receiving treatment from Dr Koh.

437 To the extent that the plaintiff subsequently developed a psychiatric disorder, as noted above, I accept the evidence of Dr Cheng and find that it is more likely that it was an adjustment disorder consequent upon the plaintiff being retrenched, rather than any significant psychiatric illness.

438 Whilst Mr Hardcastle considered that surgery might alleviate the plaintiff symptoms by releasing any pressure in the muscle, the plaintiff expressly disavowed such option. Accordingly I make no an allowance in respect of the cost of such possible future surgery.

439 It follows that I consider that the extent of any injury suffered by the plaintiff is modest.

440 In respect of the plaintiff's claim for lost earning capacity and lost income I make the following observations.

441 I accept the evidence of Mr Hardcastle and Dr Home as to the extent of the plaintiff's injury and the plaintiff's capacity to engage in his pre-accident employment as a truck driver.

442 I am satisfied that there was no significant change in the plaintiff's physical condition from 7 February 2007.

443 As the plaintiff was employed with MacMahon in his pre-incident capacity from the date of the incident on 6 December 2005 until his retrenchment on 31 January 2007 it is accepted that the plaintiff did not suffer any loss of earnings or earnings capacity during that time consequent upon any injuries he suffered.

444 I find that following his redundancy the plaintiff then remained fit to undertake his pre-incident employment.

445 Whilst Dr Manners had recommended that the plaintiff undertake a modest exercise program including swimming, stretching and strengthening with the possibly some local physiotherapy for a short period, there was no suggestion that the plaintiff would not be able to undertake his pre-accident employment. As Dr Green acknowledged, there had been no change in the physical capacity of the plaintiff to undertake his pre-accident occupation at the time of receiving Dr Williams' report and recommendation that would have prevented the plaintiff from engaging in full time employment.

446 Accordingly, I find that the plaintiff suffered no loss of earning capacity from such injury as he sustained in his fall and is not entitle to any award in respect of such loss claimed by him.

447 To the extent that the plaintiff is entitled to be compensated by the defendant in respect of any injury, loss or damage suffered at the hand of the defendant, I am satisfied that only a modest award is warranted. Such award of general damages should include an allowance in respect of medication and approximately six months mild rehabilitative treatment to relieve the calf symptoms as was recommended by Dr Williams in November 2006.

448 I consider that the appropriate measure for the damages established by the evidence consistent with my findings in respect of loss of amenities is an award of general damages in the order of $20,000 in respect of pain and suffering from the knee injury and the degree of discomfort for a period of six months where it could be reasonably be expected have resolved with a relatively modest exercise program and perhaps some local physiotherapy.

449 I further allow the sum of $1,500 in respect of medical and pharmaceutical costs to the extent that the plaintiff may require prescriptions of Lyrica from time to time and possibly some physiotherapy.