What is the test for discoverability in a medical malpractice action?

In Lawless v. Anderson, 2011 ONCA 102, 276 O.A.C. 75, Rouleau J.A. explained as follows: 22 The principle of discoverability provides that "a cause of action arises for the purposes of a limitation period when the material facts on which it is based have been discovered, or ought to have been discovered, by the plaintiff by the exercise of reasonable diligence. This principle conforms with the generally accepted definition of the term 'cause of action' - the fact or facts which give a person a right to judicial redress or relief against another.” 23 Determining whether a person has discovered a claim is a fact-based analysis. The question to be posed is whether the prospective plaintiff knows enough facts on which to base an allegation of negligence against the defendant. If the plaintiff does, then the claim has been "discovered", and the limitation begins to run. [Citations and emphasis removed] Adjournment