Grasso Consulting Engineers Pty Ltd v SafeWork NSW; Grasso v SafeWork NSW

The legislative scheme

1. Section 3 sets out the objects of the WHS Act relevantly as follows: 3 Object (1) The main object of this Act is to provide for a balanced and nationally consistent framework to secure the health and safety of workers and workplaces by - (a) protecting workers and other persons against harm to their health, safety and welfare through the elimination or minimisation of risks arising from work or from specified types of substances or plant… (2) In furthering subsection (1) (a), regard must be had to the principle that workers and other persons should be given the highest level of protection against harm to their health, safety and welfare from hazards and risks arising from work or from specified types of substances or plant as is reasonably practicable.
2. The object of the WHS Act is to secure the health and safety of workers and workplaces through the elimination or minimisation of risks by the imposition of what are described as "health and safety duties" as set out in Part 2 and the creation of categories of offences arising from a failure to comply with a health and safety duty.
3. There are different categories of offences. A category 1 offence (s 31) is dependent on the establishment of what it is described as gross negligence or recklessness. GCE was convicted in respect of a category 2 offence under s 32 which must be taken to involve something less.
4. Section 32 is in the following terms: 32 Failure to comply with health and safety duty - Category 2 A person commits a Category 2 offence if - (a) the person has a health and safety duty, and (b) the person fails to comply with that duty, and (c) the failure exposes an individual to a risk of death or serious injury or illness.
5. The offence is an offence of strict liability (s 12A). The prosecution is required to establish each element of the offence to the criminal standard.
6. In conventional terms a person will be guilty of an offence if that person has a duty, fails to comply with the duty and that failure exposes an individual to a risk of death or injury or illness.
7. There is no dispute that the appellants owed a duty. This appeal is concerned with whether they failed to comply with the duty and whether that failure exposed the demolition workers to a risk of death or injury.
8. The primary health and safety duty is set out in s 19. Sections 20 to 29 then provide for more specific health and safety duties depending on the role and type of work performed.
9. Section 27 imposes a health and safety duty on officers of the business or undertaking. Mr Grasso as an officer of GCE was found to have failed to comply with the duty imposed on him under s 27.
10. Section 19 is in the following terms: 19 Primary duty of care (1) A person conducting a business or undertaking must ensure, so far as is reasonably practicable, the health and safety of - (a) workers engaged, or caused to be engaged by the person, and (b) workers whose activities in carrying out work are influenced or directed by the person, while the workers are at work in the business or undertaking. (2) A person conducting a business or undertaking must ensure, so far as is reasonably practicable, that the health and safety of other persons is not put at risk from work carried out as part of the conduct of the business or undertaking. (3) Without limiting subsections (1) and (2), a person conducting a business or undertaking must ensure, so far as is reasonably practicable - (a) the provision and maintenance of a work environment without risks to health and safety, and (b) the provision and maintenance of safe plant and structures, and (c) the provision and maintenance of safe systems of work, and (d) the safe use, handling, and storage of plant, structures and substances, and (e) the provision of adequate facilities for the welfare at work of workers in carrying out work for the business or undertaking, including ensuring access to those facilities, and (f) the provision of any information, training, instruction or supervision that is necessary to protect all persons from risks to their health and safety arising from work carried out as part of the conduct of the business or undertaking, and (g) that the health of workers and the conditions at the workplace are monitored for the purpose of preventing illness or injury of workers arising from the conduct of the business or undertaking…
11. For the purposes of the prosecution of GCE, the respondent maintained a failure to comply with s 19(2).
12. The workers at risk were not workers engaged in GCE's business or undertaking but were said to be "other persons" (being the demolition workers on site) whose safety was found to have been put at risk from work carried out by GCE. No issue is taken as to the relationship between ss 19(1) and (2) in terms of the identification of the other persons put at risk.
13. Although the heading to s 19 refers to a duty of care and the language of s 19 includes the concept of reasonableness, a failure to comply with s 19 does not give rise to a civil cause of action. The sanction for a failure to comply is a criminal penalty.
14. Section 19(2) directs attention to whether other persons, being other than those referred to in s 19(1), were put at risk from the work undertaken by the duty holder and whether there were reasonably practicable measures which the duty holder could have taken to ensure that the health and safety of those other persons was not put at risk.
15. The question of whether other persons were put at risk from the work performed is to be considered prospectively, that is at the time the work performed by the duty holder was undertaken.
16. The principles which are to be applied to health and safety duties that are imposed upon persons are set out in s 17.
17. As s 17 makes clear, ensuring health and safety means eliminating risks so far as is reasonably practicable but, if it is not reasonably practicable to eliminate risks, then the person is required to minimise those risks so far as is reasonably practicable. The fact that the risk could not have been eliminated by a measure which it was reasonably practicable to take does not absolve the person of the obligation to take the measures provided that those measures would minimise the risk.
18. Section 18 specifies what is reasonably practicable in ensuring health and safety. "Reasonably practicable" means that which is or was at a particular time reasonably able to be done in relation to ensuring health and safety, taking into account and weighing up all relevant matters including all the matters listed in s 18.
19. The person subject to a health and safety duty is only required to do that which is reasonably practicable.
20. In Baiada Poultry Pty Ltd v The Queen [6] at [15] the majority observed (in respect of the similarly worded Occupational Health and Safety Act 2004 (Vic)): "All elements of the statutory description of the duty were important. The words 'so far as is reasonably practicable' direct attention to the extent of the duty. The words 'reasonably practicable' indicate that the duty does not require an employer to take every possible step that could be taken. The steps that are to be taken in performance of the duty are those that are reasonably practicable for the employer to take to achieve the identified end of providing and maintaining a safe working environment. Bare demonstration that a step could have been taken and that, if taken, it might have had some effect on the safety of a working environment does not, without more, demonstrate that an employer has broken the duty imposed by s 21(1). The question remains whether the employer has so far as is reasonably practicable provided and maintained a safe working environment."
21. The same approach must be taken to the duty imposed by s 19(2).
22. Demonstrating that a measure or step could have been taken and that, if taken, it might have had some effect on the safety at the workplace does not, without more, establish a breach of a health and safety duty under the Act. [7]
23. Further, it is important not to conflate non-compliance with a health and safety duty with the issue of causation which is an essential element of the offence. Breach must be assessed prospectively but causation must be assessed having regard to what actually occurred.
24. In Bulga this Court said: "[I]t was necessary to establish whether the failure to appoint an SAC was causally related to the risk of the employee's safety which occurred on the evening in question. That question is to be determined by the application of common sense to the facts in question, appreciating that the purpose of the inquiry is to attribute legal responsibility in a criminal matter". [8]
25. The causation question which arises in this matter is how or whether the conduct of GCE as particularised by the respondent was causally related to the risk to the safety of the demolition workers that occurred at the time when they were working under the roof.

The work undertaken by the appellants

1. Prior to further considering the grounds of appeal, it is necessary to say something more about the advice given by the appellants.
2. The work that was said to put the demolition workers at risk was advisory. The advice that GCE gave was the subject of considerable evidence and specific findings by the trial judge. There is no challenge to his Honour's findings as to the advice which was given, the background to it or the context in which it was given.
3. Mr Grasso did not give evidence but his record of interview with Inspector Walker on 5 October 2016 was admitted into evidence. The trial judge referred to it.
4. Mr Grasso was first invited to a site inspection on 16 March 2015. By that stage Lendlease had already entered into a contract with Hassarati to undertake the demolition of the structures on the site, including the roof.
5. It is not suggested that anything done or not done at that time is relevant to the prosecution.
6. GCE played no supervisory role on site and was not retained to supervise the demolition. There is a reference in the QCUA booklet to GCE undertaking regular inspections but it was not asked to do so by Lendlease or Hassarati and did not do so.
7. The preparation of the QCUA booklet was originally undertaken by Mr Michael Khoury from Hassarati but was taken over by Mr Tim Arnold from Lendlease commencing in October 2015. Revision H of the QCUA Booklet (a sketch) was prepared by Mr Arnold in October 2015.
8. The QCUA booklet was revised by Lendlease on a number of occasions over the ensuing year. It was intended to specify the methodology which must be adopted in undertaking the demolition work. It was provided to the demolition workers who were required to comply with it.
9. Mr Khoury said that GCE was not retained to prepare the demolition methodology documents. Mr Khoury acknowledged in cross-examination that Hassarati and Lendlease came up with the demolition methodology. There were regular meetings between Lendlease (Mr Arnold) and Hassarati (Mr Khoury) as part of the development and finalisation of the demolition methodology and the QCUA booklet.
10. Despite some evidence to the contrary (which was not accepted by the trial judge) Mr Grasso was not asked to and did not attend the demolition methodology meetings except for the meeting on 7 December 2015.
11. The QCUA booklet was up to its fourth iteration prior to December 2015. By revision H the plan or diagram in the QCUA booklet included a reference to an excavator as the decision had already been taken to demolish using an excavator rather from above using a crane.
12. In December 2015 GCE was provided with limited structural drawings and asked to prepare a sequencing layout to demolish the roof structure based on those drawings. It was not provided with the sketch contained in the QCUA booklet and was not informed that both Hassarati and Lendlease intended to demolish all of the members in any bay (other than the primary trusses) at the same time.
13. The roof structure which was to be demolished was comprised of 9 bays supported by two pairs of primary trusses (T1 to T4), 2 pairs of secondary trusses (T5 to T8) and other intermediate trusses and beams.
14. The primary and secondary trusses were to remain in situ during the demolition process being undertaken by the demolition workers at the time of the roof collapse. Those primary trusses were to be demolished at a later time using oxy-cutting equipment.
15. Mr Khoury confirmed in oral evidence that he asked GCE to advise on the sequencing (meaning the order in which members in the roof could be removed) at the request of Lendlease.
16. On 14 December 2015, GCE wrote to Hassarati enclosing a drawing which purported to set out the sequencing layout ("the 14 December 2015 report and sketch").
17. GCE identified that the demolition sequencing was preliminary at that stage and would be further refined once soft strip out was completed to expose the structural framing system of the roof. GCE prepared a colour scheme showing the staged demolition of 2 bays of the existing roof structure.
18. GCE said that its colour coordinated scheme outlined the demolition process for the bottom chord members of the roof. The sketch showed bays 3 and 4 highlighted in colour (in part) with a legend that specified a sequence of removal of the highlighted areas.
19. Hassarati did not provide the 14 December 2015 report and sketch to Lendlease. Hassarati did not inform Lendlease that the plan was only preliminary at that stage. Hassarati did not inform Lendlease of the qualification in the preliminary advice that (according to the trial judge) the discrete segments of the roof were to be demolished to ensure that the overall stability of the roof structure be maintained at all times.
20. Instead, Hassarati's general manager, Mr Khoury, created his own sketch ("the Hassarati sketch") which was then presented to Lendlease as part of the further approval of the demolition methodology.
21. On 17 December 2015, Hassarati provided the Hassarati sketch to Lendlease, without further consulting GCE. The Hassarati sketch was different to the 14 December report and sketch in a number of respects but, in particular, the Hassarati sketch did not include the colour shading in bay 3, included an excavator in the non-shaded area of bay 4 and adopted a three stage demolition sequence.
22. The GCE 14 December 2015 report and sketch were not incorporated into the QCUA booklet.
23. GCE was not consulted further about the demolition methodology until 11 February 2016 when Mr Khoury forwarded the Hassarati sketch to Mr Grasso stating: "For the sequence of the roof demolition [the] coloured plan I just sent, we want to confirm that that sequence for each bay is ok for the structural integrity of the roof and that it doesn't matter in what order each bay is demolished."
24. The Hassarati sketch specified the sequence in writing as follows: "First cut (roof sheet and purlins) Second cut (secondary beams) Third cut (primary beams)"
25. Mr Grasso responded on 11 February 2016 stating: "Further to our previous Engineers Certificate No. 01360-1 dated 14 December 2015 any bay of the roof structure can be demolished in any order in the sequence shown on the attached sketch No. 01360-SK1 dated 11 February 2016 and still maintain the integrity of the roof. Should you require any further information please contact the undersigned."
26. This advice was not expressed to be preliminary. Mr Grasso did not undertake any computer modelling or even any extensive engineering calculations.
27. Accompanying Mr Grasso's email ("the 11 February 2016 certificate") was a copy of the Hassarati sketch to which Mr Grasso had affixed a GCE stamp on it and included the words "Entertainment Centre Roof Demolition Sequencing DWG no. 01360-SK1" ("the 11 February 2016 sketch").
28. The trial judge found at [158]: "At this point, the approved methodology was changed as a result of contact between Hassarati and Mr Grasso on behalf of GCE and was now objectively comprised of three elements: (1) removal of some, but not all, of the structural members in Bay 4, which was representative for each bay; (2) removal of those structural members in a particular order; and (3) the demolition of any bay of the roof structure could take place in that sequence, in any order, and still maintain the integrity of the roof."
29. The trial judge accepted that the 11 February 2016 certificate was to the effect that the bays could be demolished in any order in the sequence shown on the attached sketch. There is no challenge to that finding in this appeal.
30. On 12 February 2016, Mr Arnold prepared a revision (revision O) of the Lendlease QCUA booklet. Included in this revision of the methodology was his own sketch ("the Arnold sketch"). Again, the Arnold sketch differed from the 11 February 2016 sketch which was certified by GCE.
31. In the Arnold sketch, the shading of bay 4 was extended so that the whole bay was covered in yellow. It was GCE's position that the shading of the whole of bay 4 altered its advice as Mr Grasso had deliberately not shaded that additional area because he intended that the structural members in the area would not be removed at the same time as the other members.
32. The evidence of both Mr Arnold and Mr Khoury was to the effect that it had always been their intention to demolish all of the structural members of each bay (that is before consulting GCE in December 2015) and that Mr Grasso knew or should have known this. There is no evidence which would have supported the suggestion that Mr Grasso should have known this.
33. The respondent asserted that Mr Grasso had just mistakenly not coloured that additional area of bay 4 but the trial judge did not accept that, finding at [177]: "Taking into account all of the evidence, I am not satisfied beyond reasonable doubt that Mr Grasso made an error in preparing the 14 December 2015 sketch or by approving the Hassarati sketch by adopting it as the 11 February 2016 sketch. It is reasonably possible that Mr Grasso did not mark some of the structural members in Bay 3 and 4 because he intended that they were to be retained to provide structural stability during the demolition of the roof structure."
34. As the trial judge was not satisfied that the leaving of the additional area unshaded was inadvertent or in error, any findings as to the advice given by GCE could only be based on the proposition that GCE's advice as to sequencing was predicated on the structural members in the unshaded area being left in place.
35. The Arnold sketch was included in revision O of the Lendlease QCUA booklet. Further, despite the differences between the 11 February 2016 sketch (which had been certified by GCE) and the Arnold sketch, the Arnold sketch was included in the QCUA booklet adjacent to the GCE engineer's certificate of 11 February 2016 as if the GCE certificate was in respect of that drawing. It was not.
36. Neither the Arnold sketch nor the revised versions of the QCUA booklet were ever provided to GCE. Nor was Mr Grasso invited to attend the final review meeting for the demolition methodology which took place on 15 February 2016.
37. As found by the trial judge at [162], the Arnold sketch had the effect of changing the approved methodology to involve only 2 elements being: 1. removal of all structural members within a bay in a particular sequence; and 2. the demolition of any bay of the structure could take place in that sequence, in any order, and still maintain the integrity of the roof.
38. The approved methodology had gone from one containing 4 elements (the 14 December 2015 report and sketch), to 3 elements (the 11 February 2016 certificate) down to only 2 elements (the Arnold sketch) which included the removal of all of the structural members within a bay. There is no evidence that the sequencing advice given by GCE involved only two elements and included the removal of all structural members within a bay.
39. The trial judge found at [199]: "I am satisfied that the Rosenlund workers undertook the demolition in accordance with the Arnold sketch and that by doing so it is reasonably possible that they removed structural members that had not been marked by Mr Grasso for removal in the 11 February 2016 sketch."
40. He also found at [201]: "I am satisfied beyond reasonable doubt that Mr Ghabache and Mr Hayward relied on GCE's advice that any bay could be demolished in any order and that the demolition proceeded on that basis."
41. The trial judge found that the demolition workers did follow GCE's advice that any bay could be demolished in any order but did not follow the advice that not all structural members should be removed (as the Arnold sketch did not contain that qualification).
42. The demolition work commenced on 4 March 2016. The demolition workers were shown the Arnold sketch and Revision P of the Lendlease QCUA booklet. Mr Hayward did not like the demolition methodology because it involved bringing down materials on top of the escalator. Mr Hayward considered that the roof structure should have been removed from above using cranes. Mr Hayward raised those concerns with Mr Arnold, but Mr Arnold assured him that the option they were pursuing had engineering approval.
43. On 7 March 2016 the demolition work continued. The order in which the bays of the roof structure were demolished was determined on site by Mr Ghabache (the site supervisor employed by Hassarati) and Mr Hayward. Initially, Mr Ghabache decided to commence the demolition at bay 3, but due to difficulties with the removal of a structural member in that bay he decided to move the excavator to bay 2.
44. Both Mr Hayward and Mr McClutchie gave evidence that the demolition proceeded in accordance with the documented sequence. On 7 March 2016 the roof structure in bay 2 had been demolished with the exception of one intermediate truss running in an east-west direction.
45. On 8 March 2016, Mr Grasso attended on site. On 8 and then 9 March 2016, he provided a revised engineer's report ("the 9 March certificate") to Mr Khoury which included the following: "We also undertook an inspection of the roof structure now that the first bay of the roof structure has been removed in accordance with the approved methodology. We confirm that demolition of the roof structure is safe and is to proceed in accordance with the approved methodology."
46. Mr Khoury explained during cross-examination that Mr Grasso was asked to attend the site at that time to inspect a box culvert and to plan for the next stage. Irrespective of what he was doing there at the time, it is apparent that he provided the March certificate on the same basis as he provided the February certificate.
47. During the period 8 March to 19 March 2016, the roof structures in bays 1, 3, 6, 7, 8 and 9 were demolished. As such, by 19 March 2016, all members and materials had been removed from bays 1, 2, 3, 6, 7, 8 and 9 exposing the primary and secondary trusses. The roof structure and ancillary fixtures remained in bays 4 and 5.
48. On 19 March 2016, Mr McClutchie was operating the excavator and Mr Hayward was acting as a spotter. During the removal of ancillary fixtures from bay 5, the remaining roof structure including trusses 1 to 8, the roof members in bays 4 and 5 and the ancillary fixtures collapsed suddenly without warning whilst the excavator was pulling down the air conditioning duct.

The cause of the collapse

1. As the duty is to not put the health and safety of persons at risk, the precise mechanism by which the roof collapsed is not determinative of breach. Indeed, having regard to the trial judge's rejection of many of the particulars of breach, some of the expert evidence is no longer relevant. However, the cause of the collapse and the expert evidence still has some relevance to the issues to be considered.
2. The respondent obtained an expert report from Professor Kim Rasmussen and Dr Mike Bambach from the Centre for Advance Structural Engineering at the University of Sydney.
3. They undertook computer modelling. They concluded that based on the modelling, the roof collapse was precipitated by lateral buckling of T5 and T6. As observed by the trial judge, lateral buckling results in a rapid loss of stiffness and load carrying capacity which led to the failure of T5 and T6.
4. Further, the experts modelled the actual demolition sequence of the roof structure, that is, the sequence adopted by the demolition workers. That modelling indicated that at the time when bays 4, 5 and 9 remained, the roof structure became unstable and was susceptible of lateral buckling of T5 to T8.
5. Dr Bambach stated the computer modelling took him 74 hours to complete.
6. As emphasised by the appellants, the experts were not asked to and did not undertake any modelling of the actual methodology proposed by GCE; that is incorporating the three elements set out at para [129] above.
7. Further, the experts agreed that providing additional lateral support for the primary and secondary trusses would increase the buckling load factor, thereby lessening the chance of collapse. That is, if the additional structural members had been left in place as advised by GCE, the chance of collapse would have been lessened.

Findings as to risk

1. The trial judge accepted that the risk was the risk of the demolition workers being exposed to a risk of death or serious injury as a result of being struck by falling objects during the course of the demolition work as a result of an unplanned structural collapse of the roof at the site.
2. His Honour found that that the likelihood of the risk occurring was high if appropriate precautions were not taken. Further, his Honour was satisfied that the appellants knew that GCE was being asked to provide structural engineering advice to eliminate or minimise the risk of an unplanned collapse of the structure during its demolition.
3. There is no challenge to these findings on this appeal.
4. His Honour went on to find that, as a structural engineer, Mr Grasso had the training and experience to devise a method that would eliminate or minimise the risk of an unplanned structural collapse. Further, he should have known that software was commercially available which could be used to model the load that is to be applied to the roof structure during demolition. The software can be used to identify load factors to assist in predicting the risk of a collapse of the remaining structure at various points of the demolition process. Again, there is no challenge to these findings on this appeal.

Findings as to breach

1. Although the particulars of breach were extensive, the trial judge found that GCE had breached the duty arising under s 19(2) only in respect of the particulars set out in paras 8(a), (e) and (f) of the Amended Summons which I have set out in para [55].
2. Whilst his Honour found that the "any bay in any order" sequence should not have been given in the absence of computer modelling, this was not the subject of any particularisation by the respondent and no finding of a breach was made on that basis.

Findings as to causation

1. The trial judge made three essential findings on causation as follows at [344]-[348]: "The creation of a computer model was a reasonably practicable measure that would have allowed GCE's advice to be tested, thereby eliminating or minimising the risk of an unplanned structural collapse. In the absence of the computer model, GCE's advice did not eliminate or minimise the risk of an unplanned structural collapse. The exercise of Mr Grasso's engineering judgement was fallible, resulting in the potential for the risk to come home during the course of the demolition. … I am satisfied that GCE's failure to adequately communicate its advice led to the interpretation of the 11 February 2016 sketch adopted by Mr Arnold and incorporated into the Arnold sketch. … I am satisfied that Lendlease, Hassarati and Rosenlund relied on GCE's advice that any bay could be demolished in any order, because Mr Ghabache and Mr Hayward were permitted by the demolition methodology to determine for themselves the order of demolition of the bays."
2. His Honour accepted that the breach of duty exposed the demolition workers to a risk of death or serious injury. The appellants challenge these findings.

The grounds of appeal

1. The grounds of appeal are extensive but, in reality, there is a ground of appeal in respect of each of the three findings of breach of paras 8(a), (e) and (f) of the Amended Summons, as well as a challenge to the findings on causation.
2. In order to succeed the appellants need to establish error of law or that the trial judge applied a wrong principle in the fact-finding exercise.
3. In oral submissions senior Counsel for the appellants summarised the errors of law on which they relied as: 1. a failure by the trial judge to assess whether the advice given by GCE would have minimised the risk; and 2. an error in finding a causal relationship between the advice given and the demolition methodology adopted when there was no evidence to support such a finding.
4. It is apparent from the way the case was conducted in the District Court that the parties approached the matter from completely different perspectives. Having regard to both the written and oral submissions in this Court, the parties continued to approach the matter quite differently.
5. On GCE's case, the respondent could not succeed without establishing that, if the demolition workers had followed the GCE advice as set out in the GCE sketch rather than as set out in the Arnold sketch, then the demolition workers would still have been exposed to a risk.
6. On the other hand, integral to the respondent's approach is that, as the focus of the legislation is on eliminating or minimising risks to persons, the critical questions are whether the measures identified by the respondent in particulars (a), (e) and (f) were reasonably practicable and whether, if taken, they would have eliminated or minimised the risk of an unplanned roof collapse.
7. Further, GCE pursues grounds of appeal 2 and 3 (and the respondent responds accordingly) on the basis that the trial judge was satisfied that particulars (e) and (f) were made out because his Honour considered that GCE had failed to properly communicate the intent of its advice (that is, there was no explicit instruction that the unshaded area should not be demolished).
8. It is not apparent from his Honour's reasoning that this is so. GCE complains that a case based on a failure to provide proper instructions on its diagram or otherwise was not pleaded but, at least on my analysis of the judgment, there is no finding of breach on this basis.

Ground 1

1. The trial judge accepted that GCE failed to eliminate or minimise the risk of an unplanned structural collapse by not undertaking design calculations in the form of computer modelling. His Honour held that that failure meant that GCE could not test any of the advice that it gave against the load factors predicted by the model to predict the risk of an unplanned structural collapse.
2. GCE submits that: 1. in making those findings, his Honour reversed the onus by imposing an obligation on GCE to establish that the methodology contained in the 11 February 2016 certificate was capable of eliminating or minimising the risk; 2. in the absence of any evidence concerning the efficacy of GCE's proposed methodology, the respondent could not establish that GCE's advice did not most appropriately manage the risk; and 3. the modelling undertaken by the experts could not establish that the 11 February 2016 certificate and sketch gave rise to the risk of unplanned structural collapse.
3. The respondent submits that the particularised engineering investigation was a stand-alone measure or step to eliminate or minimise the risk. It was something that should have been undertaken to address and manage the risk of an unplanned collapse of the roof. The respondent points to what it describes as insurmountable evidence of the requirement for such an investigation including what it describes as four streams of unchallenged evidence.
4. A finding that the taking of a particular measure was reasonably practicable is a finding of fact. It is not suggested that the trial judge applied any wrong principle or overlooked evidence or made a finding as to the availability of computer modelling absent any evidence to support that finding.
5. As the respondent submits there was ample evidence to support the availability of computer modelling including the: 1. SafeWork Australia Demolition Work Codes of Practice; 2. Australian Standard AS 2601 - 2001 the demolition of structures; and 3. expert evidence from Professor Rasmussen and Dr Bambach, as well as evidence from Mr Peter Trickett of SCP Consulting.
6. The trial judge had regard to s 275 of the WHS Act which provides that an approved code of practice is admissible in proceedings for an offence as evidence of whether a duty under the Act has been complied with.
7. Further, the trial judge was entitled to accept the expert evidence including the opinion set out at [59] of the statement of Professor Rasmussen dated 29 March 2019 as follows: "In my opinion, hand calculations would not have been adequate and structural failure analysis using numerical modelling should have been undertaken. The trusses T3 and T4, to which trusses T5 and T6 were connected, did not comprise clearly defined supports. They would have been able to move up and down and rotate in the plane of the roof where connected to trusses T5 and T6, and consequently the equations available for calculating buckling loads of T5 and T6 by hand analysis would not apply. To accurately determine the buckling load of the structure, the complete roof would have to be modelled in a finite element buckling analysis."
8. Further, in cross-examination Professor Rasmussen said: "Q. Did you prepare whether by way of handwritten note or using a calculator, any calculations, to come to the view before you did the modelling? A. No, no I did not. I could have but the uncertainty - the uncertainty that would have surrounded that calculation was such that I would much rather do an accurate computer analysis of the problem… Q. Are engineering calculations necessary to evaluate whether a structure can withstand the load imposed on it? A. See I would again say that if you do [an] accurate computer modelling calculation as we did, you would get a far more accurate [result] than what you would get by doing an approximate analysis. This structure is quite complex, it is, indeed, almost impossible to get an accurate prediction of what the buckling load would have been from a simple hand calculation. I would maintain it's impossible to get anything that would be - that you could have confidence in, would be close to what an accurate computer analysis would produce."
9. Whilst GCE was only retained on an ad hoc basis and whilst the modelling took Dr Bambach 74 hours to undertake, Mr Khoury gave evidence that there was no limitation on the work to be performed by GCE in providing its advice. The work which could be performed by GCE in providing the advice required of it (which was sequencing advice) was not limited by any particular instructions from Hassarati.
10. Any challenge to the finding that the undertaking of computer modelling was a reasonably practicable step available to GCE in February/March 2016 must be rejected.
11. Having said that, the effect of GCE's submissions appears not to be to challenge that finding but, rather to suggest that the identification of computer modelling as a reasonable practicable measure available to GCE goes nowhere without establishing how that would have eliminated or minimised the risk, to which the demolition workers were exposed at the time they were doing their work.
12. This submission blurs the distinction between findings as to breach and necessary findings as to the causation element of the s 32 offence. If this submission is directed to the question of non-compliance under s 19(2) it fails to come to terms with the proper approach to considering the question of breach. Alternatively, it is really a submission on causation.
13. The question of breach is to be addressed prospectively. As in respect of any duty expressed as a duty of care, the Court must look at the question of breach having regard to the circumstances as they existed at the time that the person on whom the duty was imposed was performing its work. The Court does not look backwards having regard to what actually happened in assessing breach.
14. Mr Grasso exercised his judgment and his judgment may have led him to come up with the correct advice (that is correct in eliminating the risk of an unplanned roof collapse) but that does not mean that that he took all reasonably practical steps to ensure the health and safety of persons that he knew may be put at risk from his work (being persons who would be working under the roof).
15. In assessing non-compliance, the Court looks at whether the duty holder has complied with the duty imposed by the section, not whether any non-compliance actually exposed the other person to a risk whilst that other person was performing his work.
16. This is similar to the approach when considering whether a person failed to take reasonable care in an ordinary civil action.
17. GCE did not ensure that the health and safety of other persons was not put at risk from its work because it did not take reasonably practicable measures to test the validity of its advice (that is that the roof could be demolished in a certain way).
18. It is no answer to suggest, in the context of advice, that it may have got it right (i.e. eliminated the risk) anyway.
19. In my view the approach of both parties tends to blur the lines between non-compliance and causation.
20. The finding of non-compliance in respect of particular (a) was open to the trial judge and no error has been shown.

Grounds 2 and 3

1. I will deal with grounds 2 and 3 together.
2. The trial judge dealt with particulars (a), (e) and (f) together. His Honour said at [279]-[281]: "I am satisfied beyond reasonable doubt that the preparation of a computer model was a reasonably practicable step that could have been taken by GCE. I am satisfied beyond reasonable doubt that GCE failed to eliminate or minimise the risk of an unplanned structural collapse by not undertaking design calculations in the form of computer modelling and was thereby in breach of its section 19(2) duty as pleaded in [8(a)] of the Summons. I am satisfied beyond reasonable doubt that GCE should not have given the 11 February 2016 advice contained in the 11 February 2016 sketch, the 11 February Engineers Certificate and the 9 March 2016 Engineers Report and was in breach of its section 19(2) duty as pleaded in [8(e)&(f)] of the Summons."
3. The findings in respect of particulars (e) and (f) were made immediately after the finding in respect of computer modelling. It was made for the same reasons. The findings must be read in conjunction with the finding relating to computer modelling. This is why the trial judge dealt with particulars (a), (e) and (f) together. The finding that GCE should not have given the advice contained in the February and March certificates must be viewed in context. It should not have given the advice without validating it through computer modelling.
4. Both GCE and the respondent focus on the findings of the trial judge as to deficiencies in the advice in terms of the diagrammatic explanation of the sequencing and the "any bay any order" advice. Implicit in the submissions is the assumption that the respondent established particulars (e) and (f) through establishing a deficiency in the content of the advice. This is not correct.
5. The finding of deficiency in the advice (that is, it was not clear) was made under the heading in the judgment "factual issues and findings" at [191].
6. The finding is a factual finding which was relevant for a number of reasons but it did not ground the finding of breach under particulars (a), (e) or (f).
7. If the trial judge intended to find that GCE was in breach of its health and safety duty under s 19(2) because it failed to make its advice clear and provide additional written instructions, I would have expected his Honour to say so. Making a factual finding that it was deficient does not constitute a finding of breach.
8. This is part of the problem with the particulars. The respondent must identify through its particulars what steps or measures GCE should have undertaken to ensure the health and safety of the other persons.
9. Indeed, it purported to do so because in the opening paragraph of the pleaded particulars the respondent alleged: "that the Defendant should have taken one or more of the following reasonably practicable steps to eliminate (or if it was not possible to eliminate, to minimise) the risk"
10. GCE could only be in breach of its health and safety duty if the respondent established that GCE did not take one of more of the reasonably practicable steps set out in particulars (a) to (f).
11. The respondent identified the undertaking of proper engineering analysis and computer modelling as one measure GCE failed to take, which was particular (a). The respondent identified the failure to assess and provide guidance that the actual demolition methodology involved a decrease in the structural integrity of the roof as another measure, which was particular (b).
12. It identified that GCE should have provided demolition methodology and procedures as another measure under particular (c).
13. Alleging that GCE should not have left its February and March certificates to be relied on of itself is meaningless without a consideration of why it should not have done so.
14. It should not have done so because it did not take a reasonably practicable measure to eliminate or minimise the risk because it did not validate the content of its advice relating to the any bay, any order sequence through computer modelling.
15. The non-compliance with the duty arising under s 19(2) was not the giving of the advice. It was the giving of the advice in February and March without undertaking the computer modelling.
16. If it were otherwise, then the respondent would need to establish that, just in leaving the certificates, GCE was putting the demolition workers at risk. It made no attempt to do so.
17. As GCE submits it could not do so without establishing that the advice did not eliminate the risk. GCE is not in breach because it gave advice. It is in breach because it failed to undertake steps which were available to it in the process of giving advice, which would have validated the advice and therefore eliminated or minimised any risk to the workers of an unplanned collapse whilst the bays were being dismantled.
18. Further, it must be remembered that his Honour rejected the respondent's case under particulars (b), (c) and (d) and considered the significance of the deficiency in the advice under particular (c).
19. His Honour was not satisfied that GCE breached its duty by failing to advise on the actual demolition methodology and sequence when Mr Grasso was not advised of the intended sequence and was not asked to inspect the progress of the demolition between 8 and 19 March 2016 (particular (b)).
20. His Honour considered particular (c) under three headings being: 1. Bay 5 should not be left towards the end of the demolition; 2. Any bay can be demolished in any order; and 3. GCE should not have provided the 11 February and 9 March 2016 engineer's reports.
21. It is under this third heading that his Honour considered the respondent's alternative arguments that the leaving of part of the sketch unshaded was either an error or a deficiency in the advice. His Honour repeated his earlier finding that the advice was deficient but then stated at [320]-[321]: "For the reasons already given, I am satisfied beyond reasonable doubt that the advice conveyed in the 11 February 2016 and 9 March 2016 Engineer's Reports should not have been given in the absence of a computer model. To the extent that the prosecution repeated its arguments that I have already dealt with, there is no utility in revisiting those matters. I am not satisfied beyond reasonable doubt that the prosecution has established this particular beyond reasonable doubt."
22. The finding of deficiency through lack of clarity or instruction was not a standalone finding of breach.
23. Indeed, his Honour expressly considered and rejected the proposition that it gave rise to breach under particular (c) and reiterated his earlier finding on breach that GCE should not have left the February certificate and March certificate in the absence of a computer model.
24. It follows that GCE's challenge to the findings of breach under particulars (e) and (f) is misplaced.
25. Having said that, again, GCE's real point on this finding is to the effect that there is an absence of any causal connection between any deficiency and the demolition workers being exposed to a risk when the demolition workers were not following the GCE advice.
26. The significance of the finding of deficiency in the context of particulars (e) and (f) is thus uncertain.
27. For the same reasons as already identified in respect of particular (a), there is no error in the finding that computer modelling was a reasonably practicable step which should have been taken for the purposes of the February or March certificates.
28. Indeed, bearing in mind that the advice given in December was expressed to be preliminary, it must be that the conduct of GCE which led to the findings of breach of the health and safety duty imposed upon it was failing to take the reasonably practicable measures at the time of giving the certificates in February and March.
29. What were the reasonably practicable measures that it should have taken when giving the advice in February and March? As particularised, it was the undertaking of computer modelling.
30. The trial judge made findings in respect to particular (f) without reference to any findings additional to those in respect of (a) and (e). If error is not established in respect of (e) then the same result would ensue in respect of (f).
31. GCE fails on grounds 2 and 3.

Grounds 4 and 5 - causation

1. It is convenient to deal with these grounds together. The grounds are extensive and are perhaps more in the nature of submissions as to why the trial judge erred in finding that the causation element of the offence was established.
2. A person commits an offence under s 32 only if the failure to comply with the health and safety duty exposes an individual to a risk of death or serious injury or illness. There must be a causal connection between the failure to comply and the exposure of persons to a risk of death or injury. This is the causation question.
3. As has often been said in the context of a negligence action, the elements of breach and causation serve different functions. [9] The former imposes a forward looking role at conduct whereas the latter imposes a backward-looking attribution of responsibility for breach.
4. The same approach applies when assessing the questions of duty, non-compliance and causation for the purposes of the offence under s 32.
5. In Rosenberg v Percival [10] Gummow J explained the role of causation as follows at [85]: "It is well understood that the legal concept of causation differs from notions of causation which appear in the speculations of philosophers and the perceptions by scientists of the operation of natural laws. This is because the legal concept of causation is primarily concerned with attributing responsibility. It has been said that the test of causation is one of common sense, but, as Lord Hoffmann has observed: '[C]ommon sense answers to questions of causation will differ according to the purpose for which the question is asked. Questions of causation often arise for the purpose of attributing responsibility to someone, for example, so as to blame him for something which has happened or to make him guilty of an offence or liable in damages. In such cases, the answer will depend upon the rule by which responsibility is being attributed.' Again, in Chappel v Hart, Gaudron J said: 'Questions of causation are not answered in a legal vacuum. Rather, they are answered in the legal framework in which they arise…'"
6. In this matter the question of causation arises for the purposes of attributing blame in the criminal context. The Court is assessing causation for the purposes of assessing whether a criminal sanction should be imposed on a person.
7. As was said in Bulga, the question is whether the acts or omissions which ground the finding of non-compliance with the duty were a significant or substantial cause of the risk to which the individual was exposed.
8. It is not sufficient that the conduct be a cause. It must be a significant or substantial cause. The use of such language tends to emphasise the importance of the conduct of the duty holder to the exposure which ultimately happened, although there may still be more than one significant cause.
9. Exposure to risk at the workplace is often multi-factorial. It is not necessary to establish that the conduct was the most important or the most significant causal factor provided it was a significant or substantial cause.
10. This is not a theoretical exercise. There must be a sufficient connection between the conduct and the individual actually being exposed to a risk.
11. Further, it is necessary to establish a causal connection between the failure/conduct and the employee (person) being exposed to the risk at the time the work was being performed (in this matter whilst the demolition workers were demolishing the roof).
12. In addressing causation, it is necessary to consider the events which actually occurred. The Court is not considering the conduct from the perspective of the duty holder when that person performed the work, that is, prospectively. The Court does that when assessing breach, i.e. whether the other persons were put at risk.
13. The trial judge made two critical findings on causation.
14. Firstly, he found that the creation of a computer model would have allowed GCE's advice to be tested, thereby eliminating or minimising the risk of an unplanned structural collapse.
15. Secondly, he found that GCE's failure to adequately communicate its advice led to the interpretation of the 11 February 2016 sketch by Mr Arnold and its incorporation in the Arnold sketch.
16. However, for the reasons that I have already identified, his Honour made no finding that the deficiency in the advice was of itself a failure to comply with the duty arising under s 19(2).
17. Nevertheless I will deal with each finding on causation.
18. The onus was on the respondent to establish causation. The respondent could not do so without establishing that the failure to undertake computer modelling exposed the demolition workers to a risk to their health and safety whilst they were undertaking their demolition work.
19. It is conceptually difficult to understand how this could be when the demolition workers were not following GCE advice and there is no evidence as what the computer modelling of the GCE sequencing advice would have shown.
20. In my view, in accepting the causal connection between the failure to undertake computer modelling and the workers being exposed to a risk to their health and safety, the trial judge erred in considering the causation question through the prism of what GCE did at the time of breach rather than how its work exposed the workers to a risk at the time they were doing the demolition work.
21. This is evident from his Honour's findings as follows at [344]: "The creation of a computer model was a reasonably practicable measure that would have allowed GCE's advice to be tested, thereby eliminating or minimising the risk of an unplanned structural collapse. In the absence of the computer model, GCE's advice did not eliminate or minimise the risk of an unplanned structural collapse. The exercise of Mr Grasso's engineering judgement was fallible, resulting in the potential for the risk to come home during the course of the demolition."
22. It is correct to say that in the absence of computer modelling GCE's advice did not eliminate or minimise the risk and thus did not ensure the health and safety as required by s 19(2) but that does not answer the question as to how or why the failure to undertake computer modelling at the time of giving the advice was a substantial cause of the risk to which the workers were exposed at the time they were doing their work, especially in circumstances in which they were not following that advice.
23. Further, it is correct to say that the exercise of engineering judgment by GCE was fallible resulting in the potential for the risk to come home during the course of the demolition but there was no potential for that risk to come home whilst the workers were demolishing the roof as a result of the advice given when the workers were not following the GCE advice.
24. The respondent falls into the same error in its submissions as follows: "There is no room for argument that causation of the risk was established by the defendants' breaches of duty. The pleaded risk could have been eliminated or if not eliminated, minimised by computer modelling of the proposed methodology or, in other words, by conducting an engineering investigation involving performing appropriate engineering analyses and undertaking design calculations. The results of that modelling or engineering investigation should have been applied. The effect of the expert evidence was that calculations without computer assisted modelling were inappropriate given the complexity of the structure. The Sketch and Advice of 11 February 2016 were deficient in that they did not make clear that the structure which was uncoloured were not to be demolished because they were necessary to provide structural stability for the roof structure during the demolition. These findings at [341]-[346] are sufficient to establish causation in this case."
25. The respondent submits that the results of the computer modelling should have been applied. That may be so for the purposes of assessing non-compliance with s 19(2) but the Court could not make a finding on the counter-factual i.e. would the workers have been exposed to a risk whilst undertaking the demolition work without knowing what the result of computer modelling would have been.
26. In my view the trial judge erred in finding that the causation element under s 32 was established, that is, the non-compliance (being the failure to undertake computer modelling) exposed the demolition workers to a risk to their health and safety. Again, this is a different question from the breach question, being whether, looking prospectively, the workers were put at risk form the failure to undertake modelling.
27. Further, the submission that the deficiency in the advice (by not making it clear) exposed the workers to a risk of death or injury does not assist the respondent without a finding of breach on this basis. However, for completeness (as the parties seemingly take a different view as to the reasons for the findings of non-compliance under particulars (a) and (e)) I will deal with that additional causation finding.
28. The reason that the workers were exposed to a risk at the time they were demolishing was because they were following the QCUA booklet and the Arnold sketch. The respondent would need to establish the causal connection between the GCE advice and the methodology adopted by the workers.
29. The trial judge accepted that the failure to adequately communicate its advice led to the interpretation of the 11 February sketch by Mr Arnold and thus the Arnold sketch.
30. In my view, that finding was not open having regard to the evidence of both Mr Arnold and Mr Khoury.
31. Both Mr Arnold and Mr Khoury gave evidence of their understanding (being that the whole area was to be demolished). This was not an understanding gained from anything Mr Grasso said or did. It was an understanding based on discussions and plans that they had made even before any involvement of GCE. Mr Khoury did not at any time inform Mr Grasso of his understanding or plan to demolish the whole of the bays at the same time.
32. In cross-examination Mr Arnold accepted that his understanding was contrary to what the Hassarati sketch showed but he said in re-examination that, if it was intended that the 200 metre (unshaded area) was to be treated in a different manner, he would have expected it to be addressed in its own right.
33. Mr Khoury prepared the Hassarati sketch. He said that it was always "the intention" (meaning Hassarati's and Lendlease's) to demolish the whole bay. He meant by this that they had formed that intention before receiving any advice from Mr Grasso. He also said that he consulted Mr Grasso because someone from Lendlease asked for a sequence certification.
34. He prepared the Hassarati sketch. He placed the excavator symbol on the unshaded area. He knew there were structural members in the unshaded area where he super imposed his excavator symbol.
35. Importantly, he said in cross-examination: "Q. When you saw the sketch you recognise[d] a sequence did not involve removing all the structure up to the truss T5? A. Yes. HIS HONOUR: Sorry, and you realise[d] that on 14 December 2015. Is that right? [A]. Yes. HIS HONOUR: Thank you."
36. He later said in re-examination that he did not pick up that the area was unshaded because he had placed an excavator over the area. I take this to mean that on later occasions he did not pick up that the Hassarati sketch left an area unshaded because he had placed an excavator symbol over the very area that was unshaded.
37. GCE's conduct (that is the lack of additional written instruction) was found to have exposed the demolition workers to a risk of death or injury in circumstances in which: 1. the person who requested and received the 2015 report and sketch advice recognised that the diagrammatic sequencing provided by GCE did not incorporate removing all the structure up to T5; 2. that same person altered the sketch received from GCE by removing some shading and placing an excavator over the unshaded area, which on his own evidence caused him not to recognise at a later time that the area was unshaded; 3. the actual advice given by GCE as contained in the GCE drawing was not passed onto Lendlease; 4. Mr Khoury and Mr Arnold plainly proceeded on an assumption or understanding which was never communicated to Mr Grasso; and 5. Mr Arnold prepared his diagrammatic representation of the demolition methodology on his understanding, formed without reference to Mr Grasso, that all of the members would be removed at the same time.
38. GCE and Mr Grasso have been found to be criminally liable for providing advice which was originally not unclear to the person who requested and received it and who changed it, which was not adopted for the purpose of finalisation of the demolition methodology, and was not relied upon or used by the persons actually exposed to risk whist undertaking the demolition work.
39. Causation involves the application of common sense in the legal context in which it is being assessed.
40. In my view, even accepting that the advice was not clear as found by the trial judge, that omission was not a substantial and significant cause of the demolition workers being exposed to a risk of death or injury at the relevant time. There were too many intervening events or factors to permit a finding that the way in which Mr Grasso depicted his advice diagrammatically and without additional words was a substantial and significant cause to the demolition workers being exposed to a risk of death or injury whist they were undertaking the demolition work.
41. In all the circumstances GCE succeeds on its challenge to the findings on causation.
42. The trial judge erred in finding that the respondent established all elements of the offence.
43. As such GCE succeeds on it appeal. The conviction must be quashed.

Mr Grasso's appeal

1. It is not necessary to say anything further about Mr Grasso's appeal. The result must be the same for the same reasons. Just as GCE succeeds on the causation grounds so must Mr Grasso. The conviction must be quashed.

GCE Appeal 1. The appeal is allowed; 2. The conviction is quashed; and 3. The respondent is to pay the appellant's costs in the District Court.

Grasso Appeal 1. The appeal is allowed; 2. The conviction is quashed; and 3. The respondent is to pay the appellant's costs in the District Court.

1. I grant leave to the parties to apply should either party seek a variation of the costs orders.

Endnotes

1. SafeWork NSW v Grasso Consulting Engineers Pty Ltd; SafeWork NSW v Ignazio Grasso [2019] NSWDC 792.
2. SafeWork NSW v Grasso Consulting Engineers Pty Ltd; SafeWork NSW v Grasso (No 2) [2020] NSWDC 188.
3. (2016) 93 NSWLR 338; [2016] NSWCCA 37 at [96] (Bathurst CJ, Hidden and Davies JJ).
4. Bulga at [96].
5. Kirk v Industrial Court of New South Wales and Another (2010) 239 CLR 531; [2010] HCA 1 at [16] (French CJ, Gummow, Hayne, Crennan, Kiefel and Bell JJ).
6. (2012) 246 CLR 92; [2012] HCA 14 (French CJ, Gummow, Hayne and Crennan JJ).
7. Baiada at [38]; Poletti Corporation Pty Ltd v SafeWork NSW [2020] NSWCCA 243 at [29] (per Macfarlan JA, Fullerton and Button JJ agreeing).
8. Bulga at [128] (Bathurst CJ, Hidden and Davies JJ).
9. Wallace v Kam (2013) 250 CLR 375; [2013] HCA 19 at [26] (French CJ, Crennan, Kiefel, Gageler and Keane JJ).
10. (2001) 205 CLR 434; [2001] HCA 18. DISCLAIMER - Every effort has been made to comply with suppression orders or statutory provisions prohibiting publication that may apply to this judgment or decision. The onus remains on any person using material in the judgment or decision to ensure that the intended use of that material does not breach any such order or provision. Further enquiries may be directed to the Registry of the Court or Tribunal in which it was generated. Decision last updated: 10 December 2021