Environmental Consultants And Other "Participant Experts" Need Not Comply With Rule 53.03

An issue often faced by environmental litigators is whether the client's environmental consultant hired prior to litigation should comply with rule 53.03 of the Ontario Rules of Civil Procedure. The case law has been inconsistent and provided no certainty as to how such evidence would be treated at trial.

In its decision released yesterday, the Ontario Court of Appeal in Westerhof v. Gee Estate, 2015 ONCA 206 (Westerhof) gave guidance and provided greater certainty as to how courts should treat opinion evidence from environmental consultants hired prior to litigation. The decision in Westerhof, a personal injury case, will have far-reaching importance for all litigators who wish to rely on opinion evidence of witnesses who formed opinions prior to litigation or who were not retained by a party in the litigation.