As clearly stated above, which is as true as the day is long, if they got you, they got you...so be respectful and cut your losses. Respect goes a long way to walking out with undamaged gear, or any gear at all. If you have to give up "tapes & batteries", just do it, look sad and remorseful and pray they allow you to stay for the rest of the show. If they want your gear, nicely tell them that you're not comfortable with that and it isn't like you can use it without the power or media. They may even give you the option to put it in your car and come back inside... this has happened to me more than once.
Again, like stated above, the law doesn't matter once you got caught. They know it, you know it, but they still have ALL the power, and will back each other up. That said, be smart.