What is the test for a motion for a new trial in a personal injury case?

adjudicated, even though incorrectly, cannot be reopened except on motion for new trial.' [Citations.] . . . (3) Petitioner 'must show that the facts upon which he relies were not known to him and could not in the exercise of due diligence have been discovered by him at any time substantially earlier than the time of his motion for the writ. . . .' [Citations.]" (People v. Shipman (1965) 62 Cal.2d 226, 230, 42 Cal. Rptr. 1, 397 P.2d 993 (Shipman).)