Re Cohen accusing Trump of a crime: (a common jury instruction):
A witness, who is willfully false in one material part of his or her testimony, is to be distrusted in others. You may reject the whole testimony of a witness who willfully has testified falsely as to a material point, unless, from all the evidence, you believe the probability of truth favors his or her testimony in other particulars.” (CALJIC No. 2.21.2; italics added.)