I listened to all 3 parts.
The guy was generally polite, but he probably should have been a bit more cooperative, ie got on the ground when told. Even though he was legal, when a cop has his gun pointed at you, it is not time to negotiate and make a stand (in my opinion). The cops were a bit overly aggressive, especially the first guy and whoever was the first of his backup.

I can almost understand one cop not knowing that open carry was legal (maybe he missed the memo), but the 7 or 8 it sounded like were present and everybody on the radio. Someone should have been able to say very quickly that it's legal for the guy to open carry; he even gave them the directive number. There was no reason it should have taken that long and still, although letting him walk free with his gun, be unclear.
I prefer concealed (no need for anyone else to know it's there) but think open should be allowed. For those that choose to do so, certain times, and when the gun is accidentally revealed, it's nice to know it's alright.
On a side note, I think the guy was looking for something like this to happen. He was already prepared with the tape recorder and knew what was required to file an internal affairs report. I don't think the average IT (his job) or most any other person would know how to do that without prior planning.
Ultimately, he was in the right but better thank God every night he's not dead.