My bet is he is a good cop. He played along with the guy, who most likely was trying to incite something more, but he ran into a cop that could think and perform his duty. I have come across more of them than the shit heads.
I witnessed a situation at an airport where some dumb ass, who was obviously joking made a bomb comment going through a checkpoint. The Sheriff had to do his job. He was more than reasonable, and yea every idiot and their cousin had their cell phone camera out recording it, but they didn't catch the part where dumb ass made the comment. The sheriff didn't cause the problem, the dumb ass who despite signs and basic common sense thought he was funny and screwed everyone who had to wait while the sheriff dealt with him. Sheriff pulled him out of line after verifying the guy was just joking, and yea, he did a full pat down and questioning before he moved him to make sure he wasn't armed and dangerous.
I also had the experience of having 2 city police come to my house after my son and his friend were shot at while driving through the city. The cops had armor under their uniforms and a vest on the outside. Are you kidding? You have to go to work wearing 2 armor vests, I guess I can see how you might be extra cautious or even be a prick to some knuckleheads. They were great and told my son and his friend what I told the 2 knuckleheads all the time, just don't drive through the city after 10 pm. What is funny about that is I would bet the morons would claim discrimination, yet no one mentioned the race of the individuals, just that it was in the city. To top it off they got shot at because a guy who ran in front of them had tried to stop a robbery and was running for his life. The shit head piles of crap were chasing him and shooting randomly.
Cops are pretty much type A people and that is probably good overall, but as with every, and I do mean every profession there are bad people and they get the headlines and not the ones that do their job the right way day after day. Examples, teachers, priests, bankers, CEOs, doctors, and as is demonstrated almost daily here, traders.
Peace