Kasim, the operator of the vehicle leased from Mazda, testified at his deposition that he was told he had suffered a stroke just prior to striking plaintiff pedestrian, which would constitute an unforeseen medical emergency. This testimonial evidence sufficiently supported Mazda's affirmative defense ( see Brewster v FTM Servo, Corp., 44 AD3d 351), and it was an improvident exercise of discretion for the trial court to preclude Mazda from presenting any such evidence at trial. Preclusion was an inappropriately severe sanction where there was neither willful behavior on Mazda's part nor prejudice to its adversary ( see Gallo v Linkow, 255 AD2d 113, 117 [1998]).