the proper response from the cop/dispatcher is "Carrying a holstered gun and being dressed funny aren't crimes here."
The rest of that 911 call goes like "I have never seen this guy around here before, he is a stranger in our neighborhood and he looks suspicious, I want you to come check him out please."
I have seen guys OC in the grocery store, restaurants, and while playing that card game "Magic The Gathering". I thought it odd with the cards but who am I to judge.
I even saw a dude OC into my bank. No alarms, guards or cops were involved and I didn't notice if the tellers looked nervous but I didn't really look for it. People have been OCing around here for a good while and most folks have seen it and don't get bent out of shape because nothing is happening. No confrontation, argument, or drama is involved at the time. It's boring looking at some guy with a gun on his belt, so what.
Now a guy with a gun on his belt being confrontational with the cops, that's going to be interesting to watch.