Forgive me for being practical, but this is one of the cases where it doesn't matter how big a liar she is - legally speaking. Even if the falsely accused sues, how can he establish she lied? That's why I think we all should be a little less gleeful when someone we don't like is accused of sexual assault, as we might be the next ones accused - and how will we defend ourselves?
Yes, I am an attorney (retired).