That flight attendant already looks like an asshole so I can totally believe he was at fault. He also fired right up against that guy who stood up against it. If he would be professional, he would have handled it differently.
Props to the guy who at least said something though he could not possibly do anything. The flight attendant knew that he could just piss him off as much as he wants and call security as soon as anything happens.
We already know there are many deplorables in the US so it isn't surprising that some of those work as flight attendants. With the recent news and people having phones with them every time, at least there is hope that those assholes will lose their job.
But god forbid, please stop record videos in portrait mode