Kmart Australia Limited v Marmara [2024] NSWCA 249

58    Kmart relied on the line of cases beginning with this Court’s decision in Makita (Australia) Pty Limited v Sprowles (2001) 52 NSWLR 705; [2001] NSWCA 305 (“Makita”) and running through to the High Court’s decision in Dasreef Pty Limited v Hawchar (2011) 243 CLR 588; [2011] HCA 21 (“Dasreef”). In Makita, Heydon JA said at [85]:

… the expert's evidence must 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. 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 specialised 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. (Emphasis supplied.)

However, in Dasreef, French CJ, Gummow, Hayne, Crennan, Kiefel and Bell JJ said at 604 [37]:

The admissibility of opinion evidence is to be determined by application of the requirements of the Evidence Act rather than by any attempt to parse and analyse particular statements in decided cases divorced from the context in which those statements were made. Accepting that to be so, it remains useful to record that it is ordinarily the case, as Heydon JA said in Makita, that ‘the expert's evidence must 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’. The way in which s 79(1) is drafted necessarily makes the description of these requirements very long. But that is not to say that the requirements cannot be met in many, perhaps most, cases very quickly and easily. That 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.(Emphasis supplied; citations omitted.)

In ELB Pty Ltd v Lumina BPO Pty Ltd [2021] NSWCA 91 at [52]-[53], after quoting the passage in Makita at [85], Beech-Jones J (Bell P and Brereton JA agreeing) said that the “apparent strictness of this statement was significantly qualified in the … passage” I have quoted from Dasreef. His Honour then said at [54]:

In this case, a specialist accountant who had worked for a particular client expressed an opinion that some item of accounting work was required to complete the client’s financial statements. That he was applying his “specialised knowledge” based on his “training, study or experience”, is a matter that required “little explicit articulation or amplification” once Mr Connolly described his qualifications and experience and identified the subject matter about which the opinion was proffered, as he did. Had it been necessary to decide this issue then, at least to the extent that Mr Connolly expressed an opinion about what was required to “Close the books”, I would have concluded that his evidence was rightly held to be admissible.

As was emphasised in Dasreef, the admissibility of opinion evidence is to be determined by application of the requirements of the Evidence Act rather than by parsing statements in decided cases divorced from the context in which those statements were made. The question under s 79 is whether the opinion is “wholly or substantially based on” the witness’s “specialised knowledge”, not whether that is made explicit on the face of the Report. That an opinion is so based may be apparent from what is expressly stated, from the immediate context in which the opinion is given, from the opinion’s place in the structure of the witness’s report, or, as is often the case, from a combination of the three. Thus, as Jagot J pointed out in Lang v R [2023] HCA 29; (2023) 413 ALR 389 at [434], citing Honeysett v The Queen (2014) 253 CLR 122; [2014] HCA 29 per French CJ, Kiefel, Bell, Gageler and Keane JJ, “the expert evidence ‘must be presented in a way that makes it possible for a court to determine that it is [substantially] based’ on the person's training, study, or experience” (my emphasis). Of course, the less the process of reasoning is made explicit, the greater is the risk that an opinion, even if based on specialised knowledge, will not be admitted into evidence because that is not sufficiently demonstrated.

A related point about opinions wholly or substantially based on specialised knowledge was made by Kiefel CJ and Gageler J, in the context of the common law principles as to admissibility of expert evidence, in Lang. At [11], their Honours said that the principles stated in Makita and acknowledged and applied in Dasreef in the context of the uniform evidence legislation apply equally to the determination of the admissibility of an expert opinion at common law. Their Honours then said at [12]:

The requirement for the opinion to be demonstrated to be the product of the application of the specialised knowledge of the expert is not absolute. In the terminology of the uniform evidence legislation, it is enough that the opinion be demonstrated to be based substantially on that specialised knowledge. Expression of the requirement in terms of substantiality recognises that specialised knowledge cannot be wholly divorced from common or ordinary knowledge and that it is “the added ingredient of specialised knowledge to the expert’s body of general knowledge that equips the expert to give his or her opinion”. The requirement will not be contravened by a process of reasoning on the part of an expert which involves using only those parts of the common or ordinary knowledge of the expert that are necessary for the expert to use in forming his or her opinion through the application of specialised knowledge.

(Emphasis supplied.)

See also per Jagot J at [435].

The mere fact that an opinion is based in part on a process of reasoning that involves common or ordinary knowledge is not a bar to admissibility under s 79, provided that the opinion is substantially based on specialised knowledge.

The point in Lang is of some significance in this case, where Kmart criticised aspects in Mr Jordan’s reasoning process, such as those in which he described and drew inferences from the CCTV footage at [8.15]-[8.19] of his report, as not being shown to be based on specialised knowledge. Whether or not those inferences were themselves based on specialised knowledge might be debatable. Mr Jordan was not a medical practitioner, as in the example in Dasreef. Nor was he an accountant, as in ELB v Lumina BPO. He was, nevertheless, an expert in a recognised field, being occupational health and safety. As in ELB v Lumina BPO, that Mr Jordan was applying his “specialised knowledge” based on his “training, study or experience”, was a matter that required “little explicit articulation or amplification” when he was expressing opinions about unsafe practices or safe systems. But even if — which I do not accept — the inferences Mr Jordan drew from footage showing the circumstances and mechanism of an incident causing personal injury were not sufficiently shown to be based on his specialised knowledge as an expert in occupational health and safety, those inferences were part of the reasoning process leading to Mr Jordan’s ultimate opinions about a safe system at [8.37]-[8.41].