How have the courts treated the error that contributed to the outcome of a jury's verdict in a civil case?

"To say that an error did not 'contribute' to the ensuing verdict is not, of course, to say that the jury was totally unaware of that feature of the trial [9 Cal.4th 426] later held to have been erroneous. When, for example, a trial court has instructed a jury to apply an unconstitutional presumption, a reviewing court can hardly infer that the jurors failed to consider it, a conclusion that would be factually untenable in most cases, and would run counter to a sound presumption of appellate practice, that jurors are reasonable and generally follow the instructions they are given. See Richardson v. Marsh, 481 U.S. 200, 211, 107 S.Ct. 1702, 1709, 95 L.Ed.2d 176 (1987) ('The rule that juries are presumed to follow their instructions is a pragmatic one, rooted less in the absolute certitude that the presumption is true than in the belief that it represents a reasonable practical accommodation of the interests of the state and the defendant').