The guy was improperly dressed per our FOM. Period. But his inappropriate response to "O" really demonstrates this guy's lack of professionalism. All he had to do was simply be polite. He could have just said, "Thanks for the advice." Then, when it was revealed to him that the person whom he was addressing was the Chief Pilot, the situation would have been far less uncomfortable. It doesn't matter if it was the SCP or a fellow crew member letting this guy know he was not in the proper attire, his crass remark was uncalled for. Using a little tact goes a long way. On top of that, wearing the company ID in civies in the AF lounge? Unsat.