How have the courts interpreted discoverability issues in a motion to determine a question of law?

The rationale for this position was recently explained by Feldman J.A. in Kaynes, at para. 81. She noted that discoverability issues are factual and it is unfair to the plaintiff for a motion judge to make such factual findings on a motion to determine a question of law under r. 21.01(1)(a), because that rule prohibits evidence on the motion except with leave of the court or on consent: In establishing the main rule that a claim should not normally be struck out as statute-barred using r. 21.01(1)(a), the courts have noted that discoverability issues are factual and that the rule is intended for legal issues only where the facts are undisputed. It would therefore be unfair to a plaintiff where the facts are not admitted, to use this rule, which does not allow evidence to be filed except with leave or on consent. But where a plaintiff’s pleadings establish when the plaintiff discovered the claim, so that the issue is undisputed, then the courts have allowed r. 21.01(1)(a) to be used as an efficient method of striking out claims that have no chance of success, in accordance with the principle approved in Knight v. Imperial Tobacco Canada Ltd., 2011 SCC 42, [2011] 3 S.C.R. 45, at para. 19.