An old friend of mine sadly found himself partly in Boston harbour in a DC-10 through no fault of his own (he was completely exonerated). It was dark and it was winter and it was snowing like hell. He threw on his raincoat to assist with the evacuation but found himself twice being manhandled into the back of an ambulance.
He kept insisting that he was the captain but the burly medics simply did not believe him and assumed him to be a passenger in a state of shock.
The reason was that he did not have his bars on his raincoat so the rescuers simply did not recognise him for what he was.
In this case, not having bars on his raincoat was a very bad move.