In determining whether to grant leave to serve a late notice of claim or to deem a late notice of claim timely served nunc pro tunc under General Municipal Law § 50-e(5), the court, in its discretion, must consider all relevant facts and circumstances, including, but not limited to, whether (1) the claimant demonstrated a reasonable excuse for the failure to serve a timely notice of claim, (2) the public corporation acquired actual knowledge of the essential facts constituting the claim within 90 days after the claim arose or a reasonable time thereafter, and (3) the delay would substantially prejudice the public corporation in its defense. No single factor is determinative, but the timing of the public corporation's actual knowledge of the essential facts constituting the claim is of great importance. In order for medical records to establish actual knowledge within the meaning of the statute, the records must establish that the medical staff, by its acts or omissions, inflicted an injury on the plaintiff.
Santos v. Westchester Med. Ctr., NY Slip Op 02802 (2d Dep't May 24, 2023)