I'm wondering why the guy on the bike even stopped in the first place. I would NEVER stop my vehicle for anyone unless I was certain they were LEO (badge, uniform, flashing lights, etc.).
A guy with a gun out in the open like that is the last person I would stop for. Plus, how many of us would have seen that gun drawn from the guy coming out of his car without ID'ing himself as a cop, and drawn our own weapons? Likely that one or both of them would be dead or seriously injured at that point.
Either way, a cop should always have to ID him/herself WITH a badge of some sort for every stop unless it's obvious they are police (cop car, uniform, etc.). This cop put everyone, including himself, in extreme danger in every way.