“The Ontario Court of Appeal in Parliament v. Conley, 2021 ONCA 261 has provided a refresher for judges, experts and counsel on the roles each plays when dealing with expert evidence:
1. Judges must exercise their gatekeeping role throughout the testimony of expert witnesses;
2. Experts must stick to the area of his or her expertise and not become advocates; and
3. Counsel are to properly instruct experts and object to inadmissible expert evidence.“
The case was a medical malpractice claim, where one of the defence experts testified as to the credibility of a witness of fact. The Court of Appeal held that the judge should have directed the jury as to whether this was appropriate. A miscarriage of justice was declared, and a retrial ordered.
Full article here.