Not sure about a law suit. In VA even though you can OC and CC with a permit, which I have, there is a small sign on one door that says no handguns. I had heard it was there and had to look hard to find it. Of course I did this after the movie and had CC'd in the theatre. Guess I'll come unarmed next time. I don't need any legal hassles. Too expensive.
I'd guess the cop could make the charge stick. Why fight what may be an expensive law suit and still possibly lose?