Generally, municipalities have at least some sort of attorney on retainer for this sort of thing.

Generally. I don't know if that's the case where he lives.

Either way, the police have to be smart enough to listen to that attorney, and have to be given a consequence for not doing so. If you can brush off everything as qualified immunity and say you were acting under color of law while a part of a union that would raise absolute hell for any sort of corrective action taken against you, you might not be introduced to said consequence.