What is the discovery date for a medical malpractice claim?

The matters referenced in section 5(1)(a) are to be considered cumulatively in order to ascertain when the claimant actually found out about the claim. That date is then compared with the section 5(1)(b) identification of the date on which a reasonable person would have found out about the claim, and the earlier of the two is the discovery date: Clarke v. Sun Life Assurance Company, 2020 ONCA 11. In the ordinary medical malpractice claim, the date that the patient learned of his or her injury is typically the discovery date, since the medical procedure the patient just underwent is self-evidently the source of the injury.