By Jonathan Thoburn ( January 23, 2020, 10:13 AM EST) -- A defendant fighting a class action will often feel that it cannot afford to leave any stone unturned when presenting evidence to defeat a certification motion. After all, a defendant can rid itself of what may be costly litigation if it can show that there is no “basis in fact” for the existence of an identifiable class, common issues and a suitable representative plaintiff, or if the defendant can demonstrate that a class proceeding would not be the preferable procedure. But can a defendant make a tactical mistake by filing too much evidence on such a motion? A recent Ontario case has answered that question in the affirmative....