Among the requirements that must be satisfied before a class proceeding will be certified is that of commonality of issues. Class proceedings statutes in the common law provinces invariably provide that the claims of class members must, in order to sustain a class action, raise common issues.[1]  However, little evidence is needed to establish that the proposed class action satisfies this requirement.  A recent decision of Belobaba J. of the Ontario Superior Court of Justice, Dine v Biomet, 2015 ONSC 7050, serves as a reminder to defence counsel that resistance to certification on grounds of insufficient commonality should primarily focus on the nature of the issue as pleaded and not on detailed evidence that speaks to the merits of the claim. Merits-based arguments based on extensive evidence are properly left to subsequent proceedings, whether in a summary judgment motion or at trial.

The plaintiff’s claims in Dine v Biomet relate to alleged injuries he suffered after receiving large-head metal-on-metal hips implants, that were designed, manufactured, and distributed by the defendants.  According to the plaintiff’s expert, large-head metal-on-metal hips implants as a class are recognized to be a problem by all surgeons.  The defendants produced three models of such implants that are at issue in the litigation.  One of the grounds on which the defendants resisted certification was insufficient commonality of issues.

Belobaba J. first confirmed that in order to establish sufficient commonality the plaintiff must adduce “some evidence” showing both that the proposed common issue exists and that it can be answered in common across the entire class.[2] With respect to the proposed common issues relating to the defendants’ duty of care, standard of care, and whether the defendants breached of that standard of care, the plaintiff adduced what would appear to be ample evidence in support of its claims, including expert evidence,[3] peer-reviewed literature,[4] and in product labelling and “instructions for use” information.[5]  The defendants attempted to challenge the sufficiency of commonality by adducing “extensive” counter-evidence including detailed counter-opinions from the defendants’ experts.[6]  Though Belobaba J. opined that the counter-evidence was “compelling”,[7] he rejected the defendants’ arguments on the well-established principle that “the certification motion is not the place for an adjudication on the merits.”[8]  Belobaba J. noted that the defendants had an upcoming summary judgment application, and he held the defendants’ arguments on these points must wait for the that hearing.[9] As a result, certification was granted on these issues.

Dine v Biomet illustrates the importance of exercising caution when deciding what kinds of arguments to advance at which stage of a class proceeding. Although the defendants in Dine v Biomet may ultimately prevail at their summary judgment application, much time and expense could presumably have been saved by refraining from making detailed evidence-based arguments at the certification motion.