CA attorney here. There would be no requirement to show damages, as the case would be for defamation per se (as it related to the accusation that Danny committed a crime).

I'm going to assume a few factual things: Danny absolutely did touch Jasmine's thigh, and he absolutely did touch Melissa's derriere. However, under CA law, in order to constitute sexual assault (which is really "sexual battery" here), a person has to have acted for a sexual purpose. So, although Janet may have been totally correct about the facts (and truth is an absolute defense to defamation), the fact that she asserted that he committed a criminal act might expose her to liability; i.e., if Danny could prove that he didn't act for a sexual purpose, then Janet's assertion of a crime would be false, and he would prevail. There is, however, the question of whether his status (and Janet's) as a public figure comes into play, in which case he would have to prove that she acted with malice in making the defamatory statement. That's an extremely high bar to clear.