I was more on Moats side until I watched the video. Could the officer have waited to write the ticket? Yes. He wasn't acting terrible or breaking any rules as a LE officer so he should have stayed on the force. There were no grounds to fire him beside pressure from the community. I've seen and heard worse. If Moats wasn't an NFL player this would not be a huge issue.
You have discretion as an officer and he could have used it there and let him go but when you are dealing with an agitated man like that, HIS demeanor is going to dictate YOURS. It's over anyway. Good luck to this guy trying to get another LE job after this.
He pulled his weapon for officer safety. The scene is not controlled and their are multiple potential suspects who may or may not be armed. Look at the random traffic stop in Oakland that left five officers dead, two of whom were making a traffic stop.