No. You don't talk to him and tell him to move on. This isn't some drunk guy approaching them in the beer tent at the county fair Cops are getting pelted with rocks, bottles, bricks and shot at. And keeping the line moving is all they SHOULD be caring about. That is their job at this point. I've never done this so I can't speak for them regarding the tension these guys felt and feel these days and I highly suggest you don't either. And that is common sense.
They were clearing the square of some, as you referred to him as, jackhole.