Good idea. My understanding:
1. Chair is ignoring points of order or otherwise breaking the rules.
2. The rule-breaking is obviously intentional, and he's ignoring everyone. Everyone is getting very angry and screaming. Chaos is breaking out. The important thing in all this is: everyone (or most everyone) can see the outrageousness and injustice of what's happening. Because you wouldn't want to do the following unless you have a majority that will back you up.
3. Lead RP person or people (few!) take out their concealed bullhorns and ask everyone to please be silent.
4. People actually get quiet. If this happens, as LostNFoundNTx said, it's pretty unlikely that the cops will arrest the lead person/people, since they are improving the situation in the cops' minds, achieving the order and calm the out-of-control chair was supposedly trying to get.
5. One lead RP person now stands in a prominent place (ideally right up close to the podium and the chair) and asks the chair to recognize a non-dilatory point of order 3 times (non-dilatory means relevant and not just a delaying-tactic. For instance, calling for division would've been good in the case of St. Charles)
6. The chair ignores these valid points of order, and let's say he even demands: "Cops, arrest that man!"
7. You've now got to do the following very quickly if the the cops are now closing in:
8. The one lead RP person declares the chair to be vacant.
9. He nominates himself for temp chair. Or, actually a lot better if the cops are looking like they might arrest him would be to nominate
someone else. This would ideally all be planned in advance. "I nominate Joe Smith." The cops have no idea who this Joe Smith is, or where he is, and besides he's protected himself by barricading himself behind a crowd of RP supporters who won't let the cops through quickly (in the case of St. Charles, he'd be way up at the top of the bleachers).
10. Someone seconds.
11. All in favor, aye. All opposed, nay. Hopefully the ayes have it very resoundingly so no count is needed, because speed is of the essence!
12. A RP person is now the temp chair. In worst case scenario the Lead Person who declared the chair vacant and made the nomination is now being dragged out and beaten Rodney King-style, but the new chair is safe for long enough he can begin conducting business.
13. He pulls out his own bullhorn (all God's children got bullhorns

) and begins doing so.