The question often arises of whether or not an Expert can, or should, provide an opinion on whether the facts they are instructed to assume and the results of their own opinion lead to a specific legal result.
Opinion evidence – expert opinion exception
Opinion evidence is prima facie not admissible (s76 Uniform Evidence Acts) because it is unreliable and potentially usurps the Judicial decision making role of interpreting facts.
An exception to the general opinion rule is expert opinion evidence (s79). Where there is a field of specialised knowledge (field of expertise) and the person has that specialised knowledge because of their training, study and experience (an expert) and provides an opinion within their expertise (expert opinion) it is likely to be sufficiently reliable to assist the Court and is therefore admissible.
Ultimate Issue Rule
There is a long history of argument that an expert should not comment on the ultimate issue for determination because that goes further than just providing an opinion within their field of expertise and, at that point, becomes inadmissible because it usurps the Judicial role.
Because of that view of the Ultimate Issue Rule expert opinions often went right up to the point where it was (hopefully) obvious what the expert thought the answer to the question for the Court was, but they did not write the concluding sentence or paragraph.
However, a proper analysis of the law relating to the Ultimate Issue Rule shows that it was always more accurately characterised as an example of the requirement that an opinion not be a mere ipsa dixit (because I say so!) statement. As the Full Federal Court stated in Arnotts v TPC:
“It is often said that an expert cannot give an opinion as to the ultimate fact that the court has to decide. This is inaccurate, as experts, especially valuers, often give evidence as to the ultimate fact, and in many cases the question whether that fact exists can be answered only by experts … What the rule really means is that an expert must not express an opinion if to do so would involve unstated assumptions as to either disputed facts or propositions of law.” (See: Arnotts Limited v Trade Practices Commission (1990) 24 FCR 313, 350 (Lockhart, Wilcox and Gummow JJ) quoting R Eggleston, Evidence, Proof and Probability (2nd ed, 1983), 147–148.)
Given the above understanding the ultimate issue rule was specifically abolished (s80) in 1995 in NSW and in other jurisdictions which apply the Uniform Evidence Act. In jurisdictions which technically retain the rule it’s proper application should not constrain an expert in the way it was so often suggested it did.
Ultimate Issue Rule – Dead but Not Buried
Despite it’s abolition, and the fact that it didn’t actually mean what it was so often cited to mean, the principles underlying the Ultimate Issue Rule are often cited to seek to constrain experts from applying a legal standard to facts, including facts which are established by their opinion.
To be clear, the expert who provides an opinion may apply a stated legal standard to facts founded on their opinion in order to fully explain their opinion, but is not entitled to purport to apply the law to the facts generally. (See Allstate Life Insurance Co v ANZ Banking Group Ltd (No 6) (1996) 64 FCR 79, esp at 83-84.)
So can an Expert provide an opinion on the ultimate issue?
So long as the opinion fully expresses all of their assumptions and the reasoning process by which they have applied their expertise to those assumed facts, and how they have applied the explicitly stated legal standard to the facts reached by their opinion.
I should note that some Counsel prefer that an expert not do so, for forensic reasons, but there is a good argument that in providing their full and transparent opinion to assist the Court the Expert should not stop just short of addressing the ultimate issue when they are in a position to do so.
This is not legal advice. I regularly conduct discussion groups on discrete issues in different areas of expert evidence to promote thinking amongst expert witnesses and those who retain them. It’s been suggested my short synopses might be of interest to others. If they are I’ll post more.
Seminars: I regularly present seminars on different areas of expert evidence for the Law Society of NSW, sometimes with experts in those fields. I am open to presenting these seminars in-house to larger firms and insurers for whom sending large numbers of people to the Law Society seminars is not practical.
Next Law Society seminar is 12 September 2017:
Dealing with clients with (possible) impaired mental capacity: with Therese Catazariti of 13 Wentworth, Professor Coyle and Alicia Tyler psychologists. http://eshop.lawsociety.com.au/index.php/catalog/product/view/id/3920