If you’re gonna accuse me of sneaking into the theater, have some proof before you approach me about what one of your employees said. In other words, do your job. It would take the manager all of five minutes to confirm what he was told. This dude paid, got concessions and yet, somehow, someone saw him sneak in through the back? White people do shyt like this to really let us know where we are and aren’t welcome and if that’s how it is, I’m a tell you about it and fukk you if you don’t like it.
Hate to break it to ya--but they don't have to show you anything. You can be arrested without "proof" of meeting your standards. Like it or not, the accusation is enough to remove you by force if necessary if you refuse. Remember, it's their establishment, not yours. You don't have a right to be there just because you think that you do.
I'm not trying to be a hard ass...but that's how it is.
Now do you have rights? Absolutely, you an sue after the fact especially when you make your case in front of a judge + you can sue the police department for the arrest and the security company. Do it the smart way--not the hard way, because while your claiming "racism", they're claiming "stop resisting."
But like I said earlier--I'd just show my ticket, get the names of everyone there, the time and get a few witnesses with phone numbers, and put in a compliant to the Manager and/or owner.