they can go to court and defend themselves if the LL files an unlawful detainer action. If the claims are not substantiated, they will not be evicted.
but to your question:
just what damages do you suggest the tenants incurred? If they want to spend a lot of money to get nothing but vindication, they might consider hiring an attorney and sue for intentional infliction of emotional distress. All they have to do is prove their claim.

