Is it possible that the FBI knows all about the Kavanaugh accuser's contacting classmates all summer long trying to find people to back-up her story and they have already investigated HER and HER antics.
That is why the FBI said they have nothing more to investigate.
The FBI has already talked to all of her classmates and his about HER ACCUSATION.
You can't prove a negative, but you can prove that SOMEONE WAS TRYING TO SET YOU UP.