Also, he might have grounds to prosecute them on federal civil Rights violations.
Exactly. He was carrying a legal permit. Unless the police saw he committed a crime he can make a prima facie case for false arrest, illegal imprisonment, and official abuse of authority under color of law. You shouldn't lose your rights just cause you happen to be a gun owner. This is still America.
BINGO! Hope he sues for enough to break them of that nasty habit for a long, long time.
In Idaho, a concealed carry is exactly that... It must be concealed. If someone saw it, it must have not been concealed.
I don't know if it's the same in Vermont, but in Idaho the fact that someone saw it would probably end your lawsuit.
He won't get far. Problem is that he was only momentarily detained and inconvienced. He wasn't arrested, removed from the premises, held, his property confiscated, or really anything. He's got very little as a case.