How have the courts interpreted jury instructions in a personal injury case?

whether or not the instructions given are correct, we must assume that the jury might have believed the evidence upon which the [defense of the] losing party was predicated, and that if the correct instruction had been given upon that subject the jury might have rendered a verdict in favor of the losing party.' " [Citations.] Where, as here, the error consisted in instructing the jury as a matter of law on a question that is one of fact on conflicting evidence, and a determination favorable to the losing party might have been made if the error had not been committed, that error is prejudicial. [Citations.]' " (Young, supra, 214 Cal.App.2d at pp. 644-645.) "[A] defendant is entitled to instructions on his theory of the case as disclosed by the evidence, no matter how weak." (Id. at pp. 645, 650; accord, People v. Salas (2006) 37 Cal.4th 967, 982-983 [in determining whether evidence is sufficient to warrant a jury instruction, the trial court does not determine the credibility of the defense evidence, but only whether there was evidence which, if believed by the jury, sufficed to raise a reasonable doubt].)

Here, there is no issue about instructions erroneously precluding the jury from considering the defendant's factual theory.