Can an expert give opinion evidence in a personal injury case?

The short answer is that such a person can give opinion evidence as this court affirmed in Westerhof v. Gee Estate, 2015 ONCA 206, 124 O.R. (3d) 721, leave to appeal refused, [2015] S.C.C.A. No. 198. It was a case about the quantum of damages for injuries suffered in a car accident. Simmons J.A. identified two types of witnesses with special expertise who can provide opinion evidence but who are not expert witnesses as described in r. 4.1.01 and Form 53: The first are “participant experts,” who form opinions based on their participation in the underlying events, such as treating physicians. The second are “non-party experts,” who are retained by a non-party to the litigation and who form opinions based on personal observations or examinations that relate to the subject matter of the case, but for another purpose. One example would be a medical examination of a claimant for statutory accident benefit insurance purposes: see Westerhof, at para. 6. (Westerhof implicitly overrules the trial decision to the contrary reached in Beasley v. Barrand, 2010 ONSC 2095, 101 O.R. (3d) 452.)