Windsor Law Faculty Author: Brian Manarin
Abstract: Professor Wigmore famously remarked that cross-examination was “beyond any doubt the greatest legal engine ever invented for the discovery of truth” (John Henry Wigmore, A Treatise on the Anglo-American System of Evidence in Trials at Common Law, vol 5, 3rd ed (Boston: Little Brown and Company, 1940) at 29, para 1367). Yet the Ontario Court of Appeal curiously declared in R v Ghorvei,  OJ No 3241 that “it is not proper to cross-examine a witness on the fact that his or her testimony has been rejected or disbelieved in a prior case,” essentially because such a finding is “no more than an opinion on the credibility of unrelated testimony given by this witness in the context of another case” (para 31). While Ghorvei involved police testimony, its ratio decidendi quickly migrated to the expert evidence arena and thus insulated expert testimony from a more scrutinizing examination. However, in White Burgess Langille Inman v Abbott and Haliburton Co.,  SCJ No 23 the Supreme Court of Canada revisited the duty that expert witnesses owe to courts and tribunals.
In White Burgess, the court held that “an expert’s lack of independence and impartiality goes to the admissibility of the evidence” (para 45). Indeed, a proposed expert witness who is unable or unwilling to provide fair, non-partisan and objective assistance to the court “is not properly qualified to perform the role of the expert” (para 53).
This article suggests that previous findings of bias against an expert witness, while arguably the functional equivalent of previous findings of incredibility, must be seen as core considerations when addressing issues of admissibility and weight given the White Burgess standard. Thus, it is argued that the rule in Ghorvei must be revisited, if not by the Ontario Court of Appeal, then by the Supreme Court of Canada.
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