Is there any case law that supports the argument that the definition of a class is too restrictive?

It must be remembered that class proceedings, as unwieldy and difficult as they may be, are intended to promote access to justice. An overly rigid technical approach to defining the class and the common issues may defeat the purpose of this legislation. Winkler, J. in Frohlinger v. Nortel Networks Co confirms at para. 28 the need for a flexible approach in assessing issues of the class definition to fulfill the purpose of the CPA: It must be remembered that the CPA is a procedural statute meant to provide a mechanism for the resolution of mass claims. As such, certification is a procedural step in the litigation and not a substantive determination. The statute must be interpreted liberally and a rigid approach to class definition based on concerns about over-inclusiveness may well defeat its purposes.