I’m inclined to believe this is what happened as well. I’ve seen this play out a few times while non-reving or deadheading in the back. I think it’s silly that either pilot can’t go into the cabin to defuse a situation but nonetheless the world we live in is cell phone recorded. Despite having done the right thing and talking to passengers in the past, now I’ll just keep the door closed until the agent/supervisor/law enforcement officer shows up and they can deal with it. I’ve had no training from any of my aviation employers on how to deal with a-holes so I’ll let the experts remove them from my cabin.