37 The approach to be taken to expert opinion evidence and it's admissibility pursuant to s 79 of the Evidence Act is relatively well settled. It was considered in some detail by Heydon JA (as he then was) in Makita (Australia) Pty Limited v Sprowles (2001) 52 NSWLR 705 at para [85] where his Honour stated:
So far as the opinion is based on facts observed by the expert, they must be identified and admissibly proved by the expert; and so far as the opinion is based on assumed or accepted facts, they must be identified and proved in some other way. It must be established that the facts on which the opinion is based form a proper foundation for it and the opinion of an expert requires demonstration or examination of the scientific or other intellectual basis of the conclusions reached. That is, the expert's evidence must explain how the field of specialized knowledge in which the witness is expert, by reason of training, study experience, and on which the opinion is wholly or substantially based applies to the facts assumed or observed so as to produce the opinion propounded. If all these matters are not made explicit, it is not possible to be sure whether the opinion is based wholly or substantially on the expert's specialized knowledge. If the court cannot be sure of that, the evidence is, strictly speaking, not admissible and, so far as it is admissible, of diminished weight.
38 The above dicta has been the subject of further and detailed consideration at first instance and appellate level. If anything, that later consideration has placed his Honour's observations in Makita at [85] above into an appropriate evidentiary context for the proper consideration and admissibility of expert opinion evidence that in no way detracts from the fundamental principles that s 79 of the Evidence Act requires.
39 The approach enunciated by Heydon JA in Makita was considered by the Full Court of the Federal Court in Sydneywide Distributors v Red Bull Australia Pty Limited (2002) 55 IPR 354. It was described by Branson J at [7] as constituting a 'counsel of perfection'. More relevantly, in the same decision, Weinberg and Dowsett JJ, by reference to [85] in Makita as set out above, expressed the following approach as properly reflecting the reception of expert opinion evidence:
[87] The use of the phrase "strictly speaking" in the last sentence should not be overlooked. It may well be correct to say that such evidence is not strictly admissible unless it is shown to have all of the qualities discussed by Heydon JA. However many of those qualities involve questions of degree, requiring the exercise of judgment. For this reason it would be very rare indeed for a court at first instance to reach a decision as to whether tendered expert evidence satisfied all of his Honour's requirements before receiving it as evidence in the proceedings. More commonly, once the witness's claim to expertise is made out and the relevance and admissibility of opinion evidence demonstrated, such evidence is received. The various qualities described by Heydon JA are then assessed in the course of determining the weight to be given to the evidence.
40 The above approach was subsequently considered and applied by Nicholson J in Australian Competition and Consumer Commission v Emerald Ocean Distributors Pty Limited (Unreported, FCA, 31 July 2002) at [6] and [7].
41 Counsel for the defendants submitted that the approach enunciated in Red Bull is properly to be distinguished from the circumstances before me in considering Professor Johnston's reports. In making that submission, counsel would appear to be relying on the views expressed by Branson J in Red Bull at [9] as follows:
It is no longer common practice for a witness from whom expert opinion evidence is intended to be adduced to be examined by opposing counsel on the voir dire . This may be because, perhaps regrettably, the practice has come to be regarded as of little practical value where the judge, and not a jury, is the trier of facts. As a result the judge is likely to be asked to rule on the admissibility of the affidavit, report or oral evidence of a witness put forward as an expert before the witness is subject to any questioning by opposing counsel. For this reason, it may prove to be the case that evidence ruled admissible as expert opinion will later be found by the trial judge to be without weight for reasons that, strictly speaking, might be thought to go to the issue of admissibility (eg that the witness's opinion is expressed with respect to a matter outside his or her area of expertise or is not wholly or substantially based on that expertise).
42 In the proceedings before me, Professor Johnston has given his evidence and has been extensively cross examined. All prosecution witnesses having been called, the Court is now in a position to make a determination as to the admissibility of Professor Johnston's evidence as an expert. In such circumstances, it was submitted, the principles espoused by Heydon JA in Makita should be strictly applied.
43 Reliance for that submission is placed on the dicta expressed by Gleeson CJ in HG v R (1999) 197 CLR 414 as follows:
[43] To paraphrase what was said by Dixon CJ in Clark v Ryan about the expert witness in that case, the evidence the defence sought to lead from Mr McCombie really amounted to putting from the witness box the inferences and hypotheses on which the defence case wished to rely.
[44] This was not a trial by jury, but in trials before judges alone, as well as in trials by jury, it is important that the opinions of expert witnesses be confined, in accordance with s 79, to opinions which are wholly or substantially based on their specialised knowledge. Experts who venture "opinions", (sometimes merely their own inference of fact), outside their field of specialised knowledge may invest those opinions with a spurious appearance of authority, and legitimate processes of fact-finding may be subverted.
44 In relying on the above passage the clear inference as submitted was that there was a stricter test for admissibility of expert opinion evidence in criminal proceedings heard by a judge sitting alone rather than the approach referred to by Branson J in Red Bull at [9]. That 'stricter test', it was submitted, was exemplified by a strict adherence to the principles enunciated by Heydon JA in Makita at [85].
45 As a reading of HG v R makes clear, the above dicta of Gleeson CJ has to be considered in light of the factual circumstances of the particular case underpinning his Honour's statement. That is, as described in Adler and anor v Australian Securities and Investments Commission (2003) 46 ACSR 504 at [631], 'the disconformity in HG v R ... to which his Honour referred was gross ...'. No such situation arises here.
46 Further, it would appear to me that counsel for CNH is being inappropriately selective in relying on but one aspect of Branson J's dicta in Red Bull as a reading of paras [8] to [10] in the judgment makes clear. More importantly, at [1] her Honour concurs generally with the reasons expressed by Weinberg and Dowsett JJ.
47 It would be reasonable to infer, in my view, that such agreement, when taken with her Honour's own comments, would embrace their Honours' dicta at [87] in Red Bull as set out at [39] above.
48 More importantly, the approach enunciated by Weinberg and Dowsett JJ, supported by Branson J, was reinforced and supported by the Court of Appeal in Adler v Australian Securities and Investments Commission at [631] as follows:
Whether an opinion has been shown to be based on the specialised knowledge is a question of fact, and s 79 provides that it is sufficient that it is substantially based on that knowledge. What is required by way of the explanation of which Heydon JA spoke in Makita (Australia) Pty Ltd v Sprowles (2001) 52 NSWLR 705 at [85] will depend on the circumstances . The disconformity in HG v R (1999) 197 CLR 414; 160 ALR 554 to which his Honour referred was gross, in that the psychologist's evidence went to when the complainant was abused and who abused her, outside a psychologist's expertise and based on matters other than a psychologist's expertise. Other circumstances will be quite different. And, as was said in Sydneywide Distributors Pty Ltd v Red Bull Australia Pty Ltd (2002) 55 IPR 354, absolute certainty that the opinion is based on the specialised knowledge is not required (at [14]) and many of the stated qualities of the opinion evidence by Heydon JA "involve questions of degree, requiring the exercise of judgment" (at [87]). (emphasis added)
49 Adopting the above approach and in considering the evidence of Professor Johnston to determine its admissibility pursuant to s 79 of the Evidence Act, it is sufficient, in my view, that I be satisfied on the balance of probabilities that Professor Johnston has drawn his opinion from known or assumed facts by reference wholly or substantially to his specialised knowledge: See s 142 of the Evidence Act.
50 There is one other matter to consider before turning to Professor Johnston's asserted specialised knowledge. That is, the objection raised by counsel for Raynjune to parts of Professor Johnston's first report on the basis that the opinion expressed fell within the well known 'ultimate issues' principle. Reliance was placed on the decision of Levine J in O'Brien v Gillespie and ors referred to above.
51 Having considered his Honour's conclusion in relation to s 80 of the Evidence Act, the ultimate issue rule, I would have to say, respectfully, that I do not agree with his Honour's conclusion on that point. Where expert opinion evidence is given that goes to 'a fact in issue or ultimate issue', it is, in my view, no longer to be considered inadmissible. Section 80 of the Evidence Act makes it clear that the previous common law and ultimate issues rules are abolished. In that respect, I concur with the view expressed by Branson J in Red Bull at [18].
52 It should be noted that in O'Brien v Gillespie his Honour concluded that the opinion evidence sought to be admitted was not expert opinion such as to satisfy the test for admissibility under s 79 of the Evidence Act.
Professor Johnston's specialised knowledge and considerations arising
53 In the reports prepared by Professor Johnston for the current proceedings, the opinions he has expressed are based predominantly, as I would understand it, on mechanical engineering principles allied with Professor Johnston's knowledge of machine design going to functionality and safety considerations in the operation of machinery generally.
54 In relation to the matters before me, the word 'functionality' is to be understood to refer to the operational function of the machine in question but with particular regard to the speed and effectiveness of the loading and unloading of the grain bin. Further, it is clear, integral to the overall functionality of the grain bin is the type, size and placement of the auger guards in the grain bin.
55 The notion of specialised knowledge for the purposes of s 79 of the Evidence Act was highlighted in the judgment of the High Court in Velevski v The Queen (2002) 76 ALJR 402 and particularly at 416 where Gaudron J stated:
The concept of ' specialised knowledge' imports knowledge of matters which are outside the knowledge or experience of ordinary persons and which is 'sufficiently organised or recognised to be accepted as a reliable body of knowledge or experience ' (citing Clark v Ryan (1960) 103 CLR 486 at 491 per Dixon CJ; Murphy v The Queen (1989) 167 CLR 94 at 111 per Mason CJ; Farrell v The Queen (1998) 194 CLR 286 at 292-293 per Gaudron J and at [28]-[29] per Kirby J; and R v Bonython (1984) 38 SASR 45 at 46-47 itself cited with approval in HG v The Queen (1999) 197 CLR 414 at 432 by Gaudron J).
56 That Professor Johnston has specialised knowledge outside the experience of ordinary persons is without doubt. His courses of study in mechanical engineering have clearly been added to by professional experience in areas related to diverse aspects of mechanical engineering and machine design embracing safety considerations that would have added to his initial specialised knowledge base.
57 The extent of Professor Johnston's knowledge and experience in a number of areas emanating from his primary expertise in mechanical engineering is well established by reference to his curriculum vitae earlier referred to. In cross examination, no challenge was made to those areas of Professor Johnston's professional background detailing, relevantly, his employment history, professional and academic areas of focus in the field of applied mechanics and machine design, amongst others, and his participation as primary or participating author in published books, journals and conference papers relevant to his areas of claimed expertise. They are, on any view, considerable.
58 In cross examination, issue was taken as to the extent of Professor Johnston's specialised knowledge and experience in relation to electrical and electronic circuitry. Professor Johnston has qualified his expertise in that area and I have earlier referred to it. I am satisfied he is able to express an opinion as to general principles relevant to electrical and electronic circuitry to the extent that such a matter has been raised in these proceedings.
59 I am, however, not satisfied that Professor Johnston is able to express an opinion as to precise steps that would need to be taken to design or modify an electrical or electronic circuit as an integral component of machine design. By his own admission, that is a matter about which he would defer to an electrical engineer.
60 Issue was taken with the Consulting Reports prepared by Professor Johnston over the period 1986 to 2005, of which there were some seventy five identified, in that none of them dealt with combine harvesters incorporating grain bins. In identifying them, Professor Johnston highlighted approximately twelve (excluding the ones prepared for these proceedings) which he stated to be generally relevant to materials or grain handling. In cross examination, Professor Johnston conceded that none of his prior consulting reports had involved consideration of mobile combine harvesters incorporating grain bins such as the machine involved in the matters now before me. Notwithstanding that, with the exception of the four prepared for these proceedings, approximately twelve of those consulting reports involved consideration of machine design across a wide variety of occupational activity.
61 For example, Professor Johnston has been involved in the preparation of consulting project reports that have required considerations and opinions going to machine design relevant to safety related issues involving machinery as diverse as a pneumatic conveyor, front-end loaders, potato bins, the handling of fish boxes, the Cat RD6 bulldozer, tractor seat runners, the walk behind mower and ride-on motor mowers. One report produced in 1996 followed Professor Johnston's appointment by the Supreme Court of New South Wales as 'a referee to enquire and report as to the cause, if any, of the overheating of the plaintiff's bulldozer'. As Professor Johnston said, his role was 'to review the overheating problem and in the process to make sense of a number of conflicting expert reports'.
62 The consultant project reports referred to, as I would understand it, were all directed to drawing upon Professor Johnston's expertise in the areas of mechanical engineering and machine design, particularly from the perspectives of occupational health and safety and materials handling.
63 No challenge was made to any aspect of those consulting reports. To put it another way, no question was put to Professor Johnston in cross examination that undermined the reliance placed by him on those specific reports, amongst others, going, as he asserted, to further establishing his expertise in mechanical engineering and machine design with particular emphasis on occupational health and safety and materials handling.
64 Further, in expressing the opinions that he does, in addition to his knowledge and experience in mechanical engineering, Professor Johnston stated that he relied upon his expertise in occupational health and safety in the context of machine design.
65 It is not entirely clear to me what Professor Johnston means when he asserts an expertise in occupational health and safety. That is a very broad and general subject matter in itself capable of complex detail across diverse industries. I am not persuaded Professor Johnston is an expert on all aspects of occupational health and safety. I am, however, satisfied that within the accepted parameters of mechanical engineering involving machine design, Professor Johnston has the knowledge and experience to enable him to express an opinion as to the principles relevant to safety considerations in machine design generally.
66 Overall, I am satisfied Professor Johnston has sufficient knowledge and experience in relation to mechanical engineering and machine design as well as safety factors relevant to machine design such as to equip him to express the opinions that he does in relation to those aspects of the machine in question. There is, however, an important rider to be placed on that conclusion.
67 It is clear that one of the fundamental issues to be determined in these proceedings will be the defence of 'reasonably practicable' as provided in s 53(a) of the Occupational Health and Safety Act 1983 with respect to CNH and s 28(a) of the Occupational Health and Safety Act 2000 with respect to Davibray and Raynjune. That defence, as I would anticipate, will, inter alia, centre around factors designed to establish that, given all the circumstances, any alteration to the current guarding of the augers in the grain bin was and is, not 'reasonably practicable'. One of the principal reasons, as I anticipate, will go directly to the issue of the functionality of the grain bin as earlier described.
68 In anticipation of such a defence, Professor Johnston has been asked to express his opinion as to how the risk to safety should have been better addressed by the respective defendants, particularly in relation to the guarding of the exposed augers in the grain bin.
69 In doing so and relying on his specialised knowledge, Professor Johnston has pointed to a number of design proposals, particularly as to guarding, designed to address the alleged risk to safety that the exposed augers in the grain bin of the machine in question currently represent. It is those proposals, inter alia, that Professor Johnston has expressed an opinion about relying on his specialised knowledge of mechanical engineering and machine design allied to occupational health and safety.
70 The proposals that Professor Johnston has expressed an opinion about involve changes to the guarding that currently exists to the augers in the grain bin, particularly the in-feed and horizontal augers. Arising from his evidence and cross examination, it is abundantly evident that design decisions as to the guarding of augers in combine harvester grain bins is significantly influenced by the impact or effect that such guarding has on the efficient and effective grain flow into and out of the grain bin. In other words, proposals about increasing and/or altering the current guarding in the grain bin in question brings with it significant argument going to the 'reasonable practicability' of such proposals relevant to the functionality of the grain bin as far as ensuring relatively unimpeded grain flow into and out of the bin.
71 While Professor Johntson has specialised knowledge about machine design allied to materials handling, his practical experience with grain flow issues as part of assessing the functionality of a grain bin is limited to his observations of a combine harvester in operation on two occasions for a limited duration for the purposes of preparing his reports in these proceedings.
72 In putting forward a number of diverse guarding proposals, Professor Johnston was unable to say with any certainty whether any of those proposals would affect the functionality of the machine and the grain bin in particular. By his own admission they are, in some respects, entirely hypothetical and/or untested or are proposals at the early research and design stage. In short, they have had no or limited testing in the field which is critical in determining the ultimate functionality and practicability of such proposals. Accordingly, at this stage, it would appear those particular guarding proposals would be unable to be relied upon to any reasonable degree as far as the Court being satisfied that the prosecution have been able to rebut any statutory defence raised as to the reasonable practicability of the particular guarding proposals put forward by Professor Johnston.
73 As Professor Johnston was unable to say the extent or otherwise to which the particular guarding proposals he identified would affect the functionality of the machine and in particular the grain bin, counsel for the defendants submitted he had strayed outside his area of specialised knowledge. In short, it was said, Professor Johnston had resorted to putting inferences of fact outside his field of specialised knowledge as identified in Clark v Ryan (1960) 103 CLR 486 at 492.
74 I have to say I do not agree. I have already identified Professor Johnston's field of specialised knowledge underpinning the opinions expressed. In relation to the guarding proposals put forward, he acknowledged functionality as a fundamental criterion if they are to be reasonably practicable and function effectively. In doing so, he has further and, in my view, quite properly acknowledged that he is unable to express a view as to the functionality of those proposals for the reasons explained. I am unable to see how that translates into Professor Johnston putting inferences of fact in support of any particular proposition the prosecution might wish to rely on.
75 The fact that Professor Johnston cannot express an opinion as to the functionality of the particular proposals he has identified is an issue that goes to weight, not admissibility.
76 Ultimately, they are matters that go directly to the statutory defences available to the defendants and any final view as to the weight to be attached will only be able to be properly determined in light of any evidence, expert or otherwise, to be adduced by the defendants.
77 As earlier indicated, in expressing the opinions that he does, Professor Johnston relies, in summation, on the general principles as enunciated in AS 4024.1 and AS/NZS 2153 Parts 1 and 7. In doing so, counsel for the prosecutor submitted, as recognized Standards, they were admissible in that Professor Johnston relied upon them in expressing the ultimate opinion that he does in relation to the machine in question. In other words, based on his own professional knowledge and experience, Professor Johnston refers to the above identified Standards as correctly stating the principles underpinning the opinions he has expressed.
78 On behalf of the defendants, it was submitted that Professor Johnston could not be considered an expert on those Standards he seeks to rely upon in expressing the opinions that he does. In support of that proposition, counsel pointed to the fact that in providing his first and second reports, Professor Johnston made no mention of AS/NZS 2153.1 and 2153.7.
79 In his first report, Professor Johnston was asked to report on the existing guarding of the grain bin and 'the extent to which they meet or fail to meet New South Wales legal requirements'. He was also asked to suggest ways in which the guarding might be improved without 'prejudicing the performance of the harvester'.
80 In providing his first report, Professor Johnston devoted a section to what he titled 'Relevant Legislation and Standards'. The Standard he identified as being relevant for the purposes of that report was AS 4024.1 - 1996, Safeguarding of Machinery, Part 1: General Principles. A copy of that Standard was produced and is exhibit 53.
81 No mention was made by Professor Johnston to AS/NZS 2153 Parts 1 and 7 in his first report or his second report. In his second report, Professor Johnston was asked to comment on a number of matters 'in relation to the issue of guarding of the horizontal augers'. Those matters were:
1.7.1 Has the issue been dealt with by workplace safety regulators, farmers' organisations or unions in other jurisdictions in Australia, or in overseas jurisdictions such as the United States, Canada, Europe or New Zealand?
1.7.2 Has the issue been referred to in agricultural industry publications?