It looks like the old man was stopped for honking. Not sure on the timing of everything, there was an injunction granted against honking downtown Ottawa.

He appears to have been arrested for refusing to identify himself when stopped (it looks like he was intending to, then emboldened by the cameraman opted not to). That's bog standard highway traffic act stuff - if you're stopped driving, you have to show your license, registration and proof of insurance if asked.

To say "arrested for honking" feels misleading - it seems reasonable to suggest that if he followed standard Highway Traffic Act stuff he would have been on his way with a warning/ticket/whatever is done presently to stop the honking, doesn't it? I'm open to have misunderstood, I'm not even qualified to be an armchair lawyer.