Partisans At The Gate: Expert Evidence And The Ongoing Duties Of The Trial Judge

Once a judge has allowed expert evidence to be admitted at trial, is the Court's "gatekeeper function" at an end? A recent decision of the Ontario Court of Appeal, Bruff-Murphy v. Gunawardena, 2017 ONCA 502, establishes that where an expert's testimony leads to questions about her impartiality at trial, the trial judge has a positive and ongoing duty to exclude the evidence or give a warning to the jury, even after the evidence has been admitted.

Facts and the Trial Ruling

Bruff-Murphy involved a claim by the plaintiff who was involved in a motor vehicle accident. The defendants admitted liability and the jury trial concerned damages. At issue was the extent of the plaintiff's injuries, including the psychological effects of the accident, including anxiety and depression.