You're right, I think the most that would happen is you are told to pack up your drone and fly elsewhere, and whether they can legally do that is often a gray area. But for me, and what I advise, don't argue with the cop, just pack it up and move to a different spot. Not that I am "rolling over" and "giving up my rights," but instead I'm protecting my pocket book and my time, both of which I value greatly. Arguing with authority often escalates the situation and you end up on the short stick. I don't want to waste my time or money fighting a BS charge and proving myself right. It is easier, faster, and cheaper for me to say, "yes sir. I believe you might be wrong, but I'll follow your request this time" or something like that, and just move on. Saves me from fighting a BS ticket.
I don't understand why some refuse to pay a $5 registration fee, but are willing to take on their local LE and ordinances, which could cost them a lot of time and money.
I think if you are really doing something patently stupid or dangerous with your drone, you will be charged with reckless endangerment. But simply flying where the local cop thinks you shouldn't won't get you in trouble unless you make a big deal out of it. Move along and do your research after to prove you were right, and present the facts you've found to your local cops, or have your research printed out to support you so that next time you can have a calm, factual interaction with the cop, with the laws/ordinances particular to your community in your hands.