Admissibility of engineering and ergonomics expert report - general discretion to exclude evidence - opinion evidence - extent of specialised knowledge
Source
Original judgment source is linked above.
Catchwords
Admissibility of engineering and ergonomics expert report - general discretion to exclude evidence - opinion evidence - extent of specialised knowledge
Judgment (25 paragraphs)
[1]
Ruling: The engineering and ergonomics expert report of Ms Margaret Sprigg dated 28 October 2025 is inadmissible.
[2]
On 18 February 2026 I ruled that a report prepared by Margaret Sprigg dated 28 October 2025 in relation to these proceedings was inadmissible. In making the ruling I indicated to the parties that I would provide my written reasons for that ruling before the end of the trial. These are my written reasons.
The plaintiff, Julie Anne Rawlins, commenced a common law proceeding in which she claims that in the course of her employment with the respondent, Coca-Cola Europacific Partners Australia Pty Limited, she suffered injuries, loss and damage caused by the defendant's negligence and/or breach of a duty under the Occupational Health and Safety Regulations 2017 (OHS Regulations). As part of the evidentiary case she seeks to advance, the plaintiff sought to adduce expert evidence in the form of a report dated 28 October 2025 authored by Margaret Sprigg from Dohrmann Consulting, described as an engineering and ergonomics expert, pursuant to Order 44.03 of the (Vic).
County Court (General Civil Procedure) Rules 2010
In both the body of the report and the resumé attached to it, Ms Sprigg sets out that she holds a Degree in Mechanical Engineering and Graduate Diploma in Ergonomics, and asserts she is a Mechanical Engineer with experience in safety, ergonomics, technical compliance and related business risk assessments. She has 30 years' experience in both the private and public sectors across a wide range of industries. Ms Sprigg claims her biomechanics experience is applicable in this case, including conducting assessment of postures and forces involved in manual handling and "the repetitive use of one's arms and hands and the relationship between the system of work and various injuries sustained by people". Ms Sprigg claims to have "audited numerous Safety Management Systems to establish their compliance with the [OHS Regulations] and WorkSafe codes of practice". Ms Sprigg claims experience in the field of Ergonomics including manual handling risk assessment and she claims to have provided expert evidence in the areas of "public liability claims including slips and falls, swimming pool diving incident; Workplace injury claims - manual handling, occupational overuse, machinery entanglement, slips and falls, farm accidents".
The defendant applied to have the proposed evidence in the report determined as inadmissible because the opinions Ms Sprigg expresses in the report are not relevant to the issues in dispute in the proceeding, the opinions lack any discernible path of reasoning and go well beyond Ms Sprigg's expertise as an engineer and ergonomist.
The defendant contended in summary that Ms Sprigg's report strays beyond ergonomics opinions into medical and legal territory, it lacks an adequate factual and methodological foundation, and risks jury confusion. It should therefore be excluded in whole (or largely in part) under the opinion rule and s 135 of the Evidence Act 2008 (Vic). In short compass the plaintiff submitted that Ms Sprigg's specialised ergonomic analysis is properly admissible under s 79 of the Evidence Act, that her use of technical literature is orthodox, that any imperfections go to weight, and that surgical redactions can remove legal conclusions and other peripheral material while preserving the report's core assistance to the jury.
Section 55(1) of the Evidence Act provides that evidence that is relevant in a proceeding is evidence that, if it were accepted, could rationally affect (directly or indirectly) the assessment of the probability of the existence of a fact in issue in the proceeding. Section 56 provides that evidence that is relevant in a proceeding is admissible in the proceeding while evidence that is not relevant is not admissible.
Section 76 of the Evidence Act concerns opinion evidence, providing that evidence of an opinion is not admissible to prove the existence of a fact about the existence of which the opinion was expressed. Section 79(1) sets out an exception to the rule against opinion evidence, providing in substance that the opinion rule does not apply to evidence of an opinion of a person with specialised knowledge based on the person's training, study or experience, that is wholly or substantially based on that knowledge.
Section 80 of the Evidence Act provides that opinion evidence is not inadmissible only because it is about a fact in issue, an ultimate issue or a matter of common knowledge.
Section 135 of the Evidence Act also contains a general discretion to refuse to admit evidence if its probative value is substantially outweighed by the danger that the evidence might, relevantly, be unfairly prejudicial to a party or misleading or confusing; or cause or result in undue waste of time.
The principles applicable to resolving questions about the admissibility of expert opinion evidence are not in dispute. In Dasreef Pty Limited v Hawchar[1] a High Court majority said when considering the admissibility of opinion evidence by application of the equivalent requirements of the Evidence Act1995 (NSW), that a two-stage inquiry is required.[2] The first is to inquire why the evidence is relevant. The majority observed:
[3]
Section 76(1) expresses the opinion rule in a way which assumes that evidence of an opinion is tendered "to prove the existence of a fact" .... the opinion rule is expressed as it is in order to direct attention to why the party tendering the evidence says it is relevant. More particularly, it directs attention to the finding, which the tendering party will ask the tribunal of fact to make. In considering the operation of s 79(1) it is thus necessary to identify why the evidence is relevant: why it is "evidence that, if it were accepted, could rationally affect (directly or indirectly) the assessment of the probability of the existence of a fact in issue in the proceeding". That requires identification of the fact in issue that the party tendering the evidence asserts the opinion proves or assists in proving.[3]
[4]
And if relevance is established, the second inquiry involves assessing whether the evidence meets two criteria. First, whether the witness has specialised knowledge based on the person's training, study or experience. Second, whether the opinion expressed by the witness is 'wholly or substantially based on that knowledge'. Accordingly the expert's evidence (here contained in Ms Sprigg's report) must ordinarily explain how the field of "specialised knowledge" in which the witness is expert by reason of "training, study or 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.[4]
But these requirements can and often are able to be satisfied very quickly and easily. As was observed in Dasreef "a specialist medical practitioner expressing a diagnostic opinion in his or her relevant field of specialisation is applying "specialised knowledge" based on his or her "training, study or experience", being an opinion "wholly or substantially based" on that "specialised knowledge", will require little explicit articulation or amplification once the witness has described his or her qualifications and experience, and has identified the subject matter about which the opinion is proffered".[5]
In Baluch v Lyndoch Warrnambool Inc and Anor,[6] Forrest J explained:
[5]
(a) the party wishing to call an expert witness must clearly identify the field of specialised knowledge in respect of which it can be said the witness can proffer an opinion;
(b) the party must then identify the expertise of the witness in that field. It must be demonstrated that by reason of specialised training, study or experience the witness is truly an expert in that area;
(c) the opinion expressed by the witness must be either wholly or substantially based on that specialised knowledge and not on the everyday knowledge of a common person;
(d) the opinion must be based on clearly identified facts;
(e) the onus rests on the party calling the witness to satisfy the criteria identified.[7]
[6]
In Dura (Australia) Constructions Pty Ltd v Hue Boutique Living Pty Ltd (No 3)[8] Dixon J considered the exception in s 79(1) of the Evidence Act and said:
[7]
In summary, the matters that will usually be considered at both stages of the inquiry that considers whether the exception under s 79(1) renders opinion evidence admissible may conveniently be referred to as four 'rules' (one of which is in three parts), which are:
[8]
(a) is the opinion relevant (or of sufficient probative value) (the relevance rule);
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> (b) has the witness properly based 'specialised knowledge' (the expertise rule);
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> (c) is the opinion to be propounded 'wholly or substantially based' on specialised knowledge (the expertise basis rule);
>
> (d) is the opinion to be propounded 'wholly or substantially based' on facts assumed or observed that have been, or will be, proved, or more specifically (the factual basis rules):
>
> > (i) are the 'facts' and 'assumptions' on which the expert's opinion is founded disclosed (the assumption identification rule);
> >
> > (ii) is there evidence admitted, or to be admitted before the end of the tendering party's case, capable of proving matters sufficiently similar to the assumptions made by the expert to render the opinion of value (the proof of assumptions rule);
> >
> > (iii) is there a statement of reasoning showing how the 'facts' and 'assumptions' relate to the opinion stated to reveal that that opinion is based on the expert's specialised knowledge (the statement of reasoning rule)?[9] (Footnotes omitted)
[9]
It may be accepted that an opinion which does no more than recite factual material or observations, and does not apply any scientific reasoning to those facts is not admissible.[10] Accordingly it is usually paramount that an expert witness set out the full reasoning by which the opinion was formed because it is only by an exposition of the expert's reasoning that the fact finder can assess the expert's evidence. As Dixon J observed in Parrish v Specialized Australian Pty Ltd[11] it is "unfair and inappropriate in proper cross examination to expect the party to challenge the lack of reasoning in the report and risk thereby drawing out some statement of reasoning of which the party has no notice".[12]
Section 80 of the Evidence Act and the composite term "fact in issue or an ultimate issue", is said to have been intended to abolish the ultimate issue rule, which rendered inadmissible opinion testimony about the ultimate issue to be determined on a case. But s 80 does not render admissible opinion evidence as to the identification of the relevant law or about its proper application.[13]
As to the operation of s 135 of the Evidence Act a Full Federal Court in Cadbury Schweppes Pty Ltd v Darrell Lea Chocolate Shops Pty Ltd[14], said:
Further, unless a witness states in his or her evidence in chief the grounds and reasoning that have led to the opinion, the opinion is valueless. Before the Court can assess the value of an opinion, it must know the facts on which it is based. If the opinion is based on irrelevant facts or facts that are clearly not going to be proved, the opinion is likely to be valueless. It should not be for a cross-examiner to endeavour to elicit the facts or assumptions upon which an opinion is expressed, and it would be unfair to leave such matters to the cross-examiner. Except in a straightforward, uncomplicated case, where the facts are admitted or otherwise readily identified, opinion evidence would normally be rejected under s 135 if the facts or assumptions upon which the opinion is based are not expressly stated.
Before turning to the specific objections it is necessary to say something briefly about compliance codes promulgated in accordance with the Occupational Health and Safety Act 2004 (OHS Act) and their effect. Part 12 of the OHS Act deals with compliance codes. By s 149 of the OHS Act, the Minister may make an order approving a compliance code for the purposes of providing practical guidance to persons having duties or obligations under the OHS Act or the regulations.
Section 152 of the OHS Act deals with the effect of a person complying with a compliance code and provides, relevantly, that if a compliance code makes provision for or with respect to a duty or obligation imposed by the OHS Act or regulations the person is for the purposes of the OHS Act and the regulations taken to have complied with the OHS Act or the regulations in relation to that duty or obligation. Section 150 of the OHS Act provides that a failure to comply with a compliance code does not give rise to any civil or criminal liability.
The impugned report is structured into nine sections or parts each containing a number of paragraphs. Part 1 deals with Ms Sprigg's qualifications and experience ([1.1] - [1.9]). Part 2 sets out the instructions and scope of the report ([2.1] - [2.4]). Part 3 sets out the documents and materials Ms Sprigg read or examined ([3.1] - [3.6]). Part 4 is headed "assumed facts" ([4.1] - [4.23]) but deals with much more than describing facts assumed for the purposes of preparing the report. Part 5 ([5.1] - [5.3]) is headed "no inspection" and sets out that the report is based on briefing material supplied and an interview with the plaintiff and that no view of any of the worksites was undertaken. Part 6 is headed "standards and guidance material" ([6.1] - [6.7]) and sets out various compliance codes, codes of practice and various literature to which reference is made in the report. Part 7 is headed "discussion and analysis" ([7.1] - [7.5]). Part 8 sets out the questions that were asked and the answers Ms Sprigg gives to each question (18 questions in total). Part 9 contains an expert code of conduct declaration and thereafter a resumé is attached.
The defendant has raised objection to numerous paragraphs of Ms Sprigg's report and ultimately submitted that the report in its entirety is inadmissible. During the course of argument I canvassed with the plaintiff's Counsel whether excising or redaction of some aspects of the report, including the questions posed, might render the report admissible. That exchange is recorded in the transcript and need not be here repeated. For reasons to which I will shortly come, I have concluded that excising or redaction is no answer to the concerns about admissibility.
I consider the whole report is inadmissible because many aspects of Ms Sprigg's report are not grounded in her specialised knowledge or expertise as a mechanical engineer/ergonomist. Many of her opinions rest on or involve medical questions as is evident from her discussion of causation, ligament injuries, and diagnosis, which are outside her expertise. And the report contains assertions or opinions unsupported by reasoning based on her specialised knowledge, sometimes based on assumptions or are based on literature of questionable relevance and providence.
On a review of Ms Sprigg's report, she frequently sets out or expresses views that are medical in nature and beyond her expertise, including her statements about the plaintiff suffering particular ligament injuries, and the circumstances in which the injuries were sustained - particularly the 2 September 2021 incident which is contested (for example at [4.11] and [4.12]). The discussion about "gamekeeper's thumb", causation of ligament tears, and the biomechanics of injury (for example at [4.22], [7.1], [8.1(1)], [8.2(11)]) and her opinions about whether particular actions could or did cause particular injuries, as well as her assessment about the circumstances of the plaintiff's return to normal duties [8.1(7) and (8)] are all matters outside her specialised knowledge or expertise as a mechanical engineer/ergonomist.
Ms Sprigg's reliance on a study about college student use of smartphones and the asserted impact of smartphone use, duration and posture on the prevalence of hand pain compounds the problem in that she relies on the report, not her own expertise or specialist knowledge to opine that it was not safe or sustainable for the plaintiff to have performed work duties related to the use of the mobile phone with a pop socket attachment and an iPad having regard to her pre-existing thumb injury.
Moreover Ms Sprigg's report does not establish that this study is a recognised authoritative piece of literature on the subject matter. Contrary to the plaintiff's contention I do not consider the defendant should bear the obligation to "call for" or investigate external literature to understand or cross‑examine Ms Sprigg. Nor should the defendant be forced to remedy a deficient expert report by eliciting reasoning in cross‑examination. Ms Sprigg's report relies on external research and articles at [4.22] and [4.23] which is not shown to be within her specialised knowledge.
Ms Sprigg's report recites and purports to interpret and apply statutory OHS obligations. The report wrongly refers to WorkSafe Victoria compliance codes as if they establish legal duties. As s 150 of the OHS Act makes clear, a failure to comply with a compliance code does not give rise to any civil or criminal liability. In the result Ms Sprigg's expresses conclusions such as "Coca‑Cola was not in compliance with the OHS Regulations" and that the "requirements of the WorkSafe Compliance Code had evidently not been met". In combination [4.20], [4.21], [7.1], [7.2], and parts of [8.1(1) and (3)] purport to analyse the law and reach conclusions about its application in the circumstances identified. Plainly legal conclusions about the operation and effect of the OHS Regulations and compliance codes are matters well outside Ms Sprigg's specialised knowledge or expertise as a mechanical engineer/ergonomist. These opinions are not saved by the operation of s 80 of the Evidence Act, because as I have earlier explained, that section does not render admissible opinion evidence as to the identification of the relevant law or about its proper application. Ms Sprigg's references to WorkSafe compliance codes and risk assessment worksheets are, in light of s 150 of the OHS Act, legally meaningless, and in the circumstances they are apt to mislead because the report suggests that these are mandatory standards with which the defendant had to comply. Their inclusion in the report and the opinions framed around them are wrongheaded and would unfairly prejudice the defendant.
Aspects of the report are not relevant to any issue in this case. For example the reference to Coca-Cola not providing the plaintiff with a trolley [7.3]; the reference to matters which were said to have been "widely available to employers (through publications in the trade, industrial and general media) for a number of years prior to the occurrence of this injury" [7.5]; and Ms Sprigg's opinion that "employers have for some time had opportunities to access such materials (or other information) as a means of familiarising themselves with risks to which their employees may be exposed, with a view to eliminating or at least minimising these risks" [7.5] - an opinion which also appears to be outside of her area of expertise.
I agree with the defendant's contention that the report assumes particular facts about hand‑height positions; grasp widths; forces applied; and how many bottles were handled and gives speculative opinions "without knowledge of the actual forces involved (as these will vary depending on the way in which the bottle is handled) it would nevertheless be reasonable to assume" [8.1 (2)]. Moreover the report makes reference to the purported fact that the requirement to face up bottles "is not standard industry practice" but Ms Sprigg does not identify the industry to which she refers nor does she specify the basis upon which having regard to her experience and specialist knowledge she could reach such a conclusion. All the more so in circumstances where, as is clear from Part 5 of her report, no inspection of any worksite at which the plaintiff attended was visited. Ms Sprigg's opinion that the task of facing up could be eliminated is given without any evident expertise and is irrelevant and gratuitous.
The plaintiff submitted that Ms Sprigg is a properly qualified expert in Ergonomics and Mechanical Engineering. I do not doubt that that is so but I do not accept, for the reasons identified above that the opinions in the report are based on her specialised knowledge. As I have sought to identify, her opinions stray well beyond her expertise. That Ms Sprigg made the expert code of conduct declaration and stated that she was satisfied that the information available justified her opinions, is not to the point. On the plain reading of the report it is clear the report is replete with the difficulties I have identified above. As earlier mentioned, during the course of argument the plaintiff accepted that certain passages of the report should or could be removed, including those related to or containing discussion of causal linkage, legal conclusions, the questions asked of Ms Sprigg and the more speculative, repetitive and medical fragments of the report. Ultimately the report suffers from too many flaws and the tendering of redacted answers given without identifying the questions to which they are responsive would remove important context, so as to render excisional redaction futile and leaving little left in the report.
My overall impression is that the entirety of Ms Sprigg's report is inadmissible. As explained above several of the opinions proffered travel well outside her area of expertise; some opinions about compliance codes and the defendant's obligations by reference to a compliance code are plainly wrong. Other opinions about compliance with statutory or regulatory obligations are also outside of her expertise. Some of Ms Sprigg's opinions lack proper factual foundation or lack a path of reasoning. Ms Sprigg opines about medical matters including medical causation and aspects of the report offer speculative and legally irrelevant opinions.
I make a final observation. It ought be self-evident that an expert witness is not an advocate for a party in the proceeding. The expert may give opinion evidence which is probative of a fact in issue, if the opinion is based on the expert's specialised knowledge. An expert's role is not to argue the case of the retaining party. Drafting questions for expert witnesses to answer in a way that seeks an opinion on the ultimate legal issue for decision may invite tendentious opinion that is unhelpful and irrelevant. As Sheller JA said (with Mason P and Meagher JA agreeing) in Faucett v St George Bank Ltd[15]:
[10]
Mr Jennings should not have been asked nor permitted to give evidence such as that set out in paras 10.1 and 10.2 which I have quoted. It was not part of the function of this expert to state as his opinion that the respondent failed in its duty to provide a safe system of work or to provide a security system which was commensurate to the obvious risks of robbery. Section 80 of the Evidence Act 1995 provides relevantly that evidence of an opinion is not inadmissible only because it is about (a) a fact in issue or an ultimate issue. But as Mason P pointed out in R v GK[2001] NSWCCA 413; (2001) 53 NSWLR 317 at 326-7, "judges should exercise particular scrutiny when experts move close to the ultimate issue, lest they arrogate expertise outside their field or express views unsupported by disclosed and contestable assumptions." In Allstate Life Insurance Co v Australia & New Zealand Banking Group Ltd (No 6) (Court's `Allstate' Judgment No 33)(1996) 64 FCR 79 at 83 Lindgren J said:
[11]
"I find it convenient at the outset to state some principles of the general law against which, in my view, the effect of par 80(a) is to be determined. It is fundamental that the ascertainment of the law relevant to a matter before a court and its proper application to the facts of the particular case are of the essence of the judicial function and duty. Although those processes are properly the subject of submission, evidence of opinion, whether as to the identification of the relevant law or as to its proper application, is not admissible. The rationale underlying this fundamental principle may be expressed in various closely related ways: to admit such evidence would be to permit abdication of the judicial duty and usurpation of the judicial function; such evidence cannot be allowed to be probative or to rise higher than a submission; such evidence is necessarily irrelevant."
[12]
With his Honour's statement I entirely agree . . .[16]
[13]
The appropriate course in the circumstances is to rule as I have that the report in its entirety is inadmissible.