This is a post purely to indulge my pedantry. In Reece v. Toronto (Police Services Board), the Court of Appeal said this about discovery:
 The motion judge correctly found that discoverability for the purpose of limitations is based upon knowledge of the facts necessary to support a claim and does not require knowledge of the law that supports the claim.
This isn’t quite right. Discoverability for the purpose of limitations–what other purpose to does the principle have?–is codified in s. 5 of the Limitations Act and requires knowledge of the four discovery matters. The facts necessary to support a claim are, pursuant to the definition in the s. 1 of the Limitations Act, but only two: wrongful conduct and resulting loss. The existence of a claim and the discovery of a claim are different issues.