Maybe the biker wasn't completely in the right beeping, but once the confrontation started, the biker was calm and fairly articulate.
The cop acted like a bully doing what ever he could to try to escalate the situation into a serious confrontation.
I'm pretty sure I would have asked the cop "am I under arrest for beeping at you while you were talking on the phone impeding traffic?", if the cop would have said anything other than yes, I would have a driven away. Just watching that video started putting me into a fight or flight mentality. That video should go to that cops department and 9 News, he proved he has no ability or desire to diffuse a confrontation and is a liability.