Limitations Act - Discoverability - Defendant Identity [s.5]. Gillham v. Lake of Bays (Township)
In Gillham v. Lake of Bays (Township) (Ont CA, 2018) the Court of Appeal case the court canvasses general principles of discoverability under limitations law:
 The overarching question in the discoverability analysis under s. 5 of the Act is whether the claimant knew or reasonably should have known, exercising reasonable diligence, the material facts stipulated under s. 5(1)(a) that give rise to a claim: Ferrara v. Lorenzetti, Wolfe Barristers and Solicitors, 2012 ONCA 851 (CanLII), 113 O.R. (3d) 401, at para. 32. Section 1 of the Act defines a claim as “a claim to remedy an injury, loss or damage that occurred as a result of an act or omission”. Section 2(1) provides that the Act “applies to claims pursued in court proceedings” (with certain enumerated exceptions that do not apply here).. Zabanah v. Capital Direct Lending Corp.
 Knowledge of the claim includes knowledge of the identity of a potential defendant, although it is not necessary for a claimant to know with certainty a potential defendant’s responsibility for an act or omission that caused or contributed to the loss. As this court observed in Longo v. MacLaren Art Centre, 2014 ONCA 526 (CanLII), 323 O.A.C. 246, at para. 44: “All that is required is that the plaintiff has prima facie grounds to infer that the acts or omissions were caused by the identified parties.”
In Zabanah v. Capital Direct Lending Corp. (Ont CA, 2014) the Court of Appeal clarified what degree of certainty is required before it can be said that a plaintiff has 'discovered' a cause of action for purposes of triggering the running of a limitation period:
 The appellant’s discoverability argument was that she did not know who was responsible for her loss, injury or damage until 2011. In addressing this argument, the motion judge concluded that by April 2008, the appellant had the knowledge to infer that Capital Direct may have been the cause of her loss. She relied on this court’s statement in Kowal v. Shyiak, 2012 ONCA 512 (CanLII), 13 C.L.R. (4th) 7, at para. 18, that:
Certainty of a defendant's responsibility for the act or omission that caused or contributed to the loss is not a requirement. It is enough to have prima facie grounds to infer that the acts or omissions were caused by the party or parties identified.