In a recent decision, Madam Justice Ellen MacDonald refused to permit a defence expert to give opinion evidence at trial. After reviewing a series of email messages that had been exchanged between the expert and certain of the defendants and after conducting a voir dire, she concluded that the expert’s “role as an independent expert was very much secondary to the role of ‘someone who is trying to their best for their client to counter the other side'” and refused to allow the expert’s opinion into evidence.
The expert in question, Ronald Anson-Cartwright, was retained by some of the defendants to assist with some financial and accounting issues. On the voir dire before Justice MacDonald, it emerged that in his report, Mr. Anson-Cartwright had “based his analysis of the defence position on the theories advanced by Mr. Piersanti [a defendant]. In his closing submissions on the voir dire, Mr. Diamond [counsel for the plaintiffs] stated that the two reports ‘are replete on every page with not only findings of fact, findings of credibility, but conclusions as to what the evidence is literally and what legal conclusions should be, not just factual conclusions’.” Her Honour seems to have accepted this submission, as she found that Mr. Anson-Cartwright was “disqualified as an expert in this case”.
Her Honour cited various cases as authority for the role of the trial judge as “gatekeeper” when it comes to expert evidence.
To the extent that there really is a requirement for experts to be impartial (as to which, see our comments at the end of this post), we think that Justice MacDonald’s analysis is sound. However, we are somewhat concerned about fhe factual underpinnings of the decision. Unfortunately, not much detail is given in the reasons as to just what was so objectionable about the correspondence exchanaged between the expert and the defendants. What appears to have troubled the judge the most was the expert’s reliance on theories that had been given to him by the one of the defendants. Justice MacDonald observed that as a result, Mr. Anson-Cartwright “did not complete independent verification of key issues in accordance with the standards that are expected of an expert”.
We would have thought that shortcomings in the factual investigation done by the expert would more properly be the subject of cross-examination at trial. Or, if the case were one in which the expert had been asked to render an opinion based on a hypothetical set of assumptions, then cross-examination would presumably have demonstrated that the assumptions could not be proved. It will often be the case that, to some extent, the expert has been given an incomplete and perhaps even a slanted version of the facts. We would not expect this factor alone to disqualify him or her, at least not on grounds of lacking impartiality. How much the facts relied on by this expert were coloured by their source is difficult to determine from the decision, since the reasons contain no examples or excerpts from the email messages.
However, Justice MacDonald clearly did also think that the expert had become an advocate for the defendant who had retained him. Again, it would have been helpful to have some examples showing how this partisanship had manifested itself here, so that the practicins bar might better be able to judge what is kosher and what is not.
The extent to which an expert must be impartial in order to be able to give opinion evidence is, we think, not so clear as this decision would suggest. Four years ago, in Tri-Co v. Paterson, one of us was before the Court of Appeal, arguing that the plaintiff’s principal witness at trial (the plaintiff’s accountant) ought not to have been permitted to give evidence as a lay witness and that he could not have been qualified as an expert because he was not impartial. The Court of Appeal pooh-poohed this argument. (Actually, it agreed with the first submission but not the second.) The Court said in that case:
While there may be limited circumstances in which an otherwise qualified expert would not be permitted to give expert evidence because of lack of neutrality (rather than have the weight given to their evidence diminished), in our view, this is not such a case. Mr. Simpson’s long association with the respondent made him the ideal person to give the fact evidence that formed the underpinning of the lost profits calculation. To the extent that Mr. Simpson’s evidence may have crossed the line into opinion, it did not duplicate the evidence of other witnesses and the trial judge took account of its frailties in assessing its weight. In the circumstances, we are not persuaded that admitting Mr. Simpson’s opinion evidence amounted to reversible error. [Emphasis added]
In the course of argument, the panel questioned whether it was really true, as suggested by Bank of Montral v. Citak and several other trial level decisions, that it is imperative that an expert be impartial. One member of the panel gave the example of police officers testifying at criminal trials arising out of motor vehicle accidents. There is no suggestion, said the justice, that the officers are impartial, but they are not prevented from giving expert testimony on that basis.
So, we await with interest the Court of Appeal’s view of the “limited circumstances” in which the permissible limits of partiality are exceeded by an expert witness. For the time being, we are uncertain as to what those limits might be.