What is the basis for reversal of judgment in a personal injury case?

basis for reversal of the judgment in the absence of identifiable prejudice or "gross unfairness ... such as to deprive the defendant of a fair trial or due process of law." [Citations.] (People v. Cummings , supra , 4 Cal.4th at p. 1287, 18 Cal.Rptr.2d 796, 850 P.2d 1....)" (People v. Taylor (2001) 26 Cal.4th 1155, 11731174, 113 Cal.Rptr.2d 827, 34 P.3d 937.)