What is the test for determining whether a jury has found a particular theory of liability in a motor vehicle accident?

Normally, the failure of a jury to find a particular theory is not an issue that arises on appellate review. Jurors need not agree on a single theory of liability. Schad v. Arizona, 501 U.S. 624, 645, 111 S.Ct. 2491, 115 L.Ed.2d 555 (1991). And jurors are presumed to be capable of determining which theory of liability, if any, fits the facts of a particular case. Griffin v. United States, 502 U.S. 46, 59, 112 S.Ct. 466, 116 L.Ed.2d 371 (1991). The issue of whether a jury has found a theory is usually not a question for an appellate court.