What is the test for a jury to convict a defendant of assault?

In People v. Flores, supra, 17 Cal.App.3d 579, 95 Cal.Rptr. 138, the jurors returned to the courtroom after deliberating approximately three hours. The foreman reported that the jury had not yet been able to reach a verdict and was divided five to seven. The trial court then analyzed the credibility of the two testifying witnesses, the defendant and the arresting officer, and stated its conviction as to the defendant's guilt. Thereupon, the jury continued its deliberations and rendered a guilty verdict.