Can a jury overturn a defendant's conviction for assault?

We may not reverse defendant's conviction simply because differing inferences and findings could have been made by the trier of fact. "[A]n appellate court may not substitute its judgment for that of the jury. If the circumstances reasonably justify the jury's findings, the reviewing court may not reverse the judgment merely because it believes that the circumstances might also support a contrary finding. [Citations.]" (People v. Ceja, supra, 4 Cal.4th at p. 1139.)