Don't they have security cameras in your dad's workplace? He should have asked for proof of it and bring legal help, seriously. He stood by to having a criminal record for that bitch?
It is becoming more and more common to file countersuit for false claims like that.
Thing is guys, I asked my mom about this, and she said "we can't afford a lawyer". And even if we could, the only evidence we could use is my dad's word, because (and this is answering your question here), they don't have cameras in the lab where my dad works.
So we just have to live with it and move on. I think and I hope my dad will retire soon.