So the officer is suppoosed to somehow magically know that this isn't an escaped felon, just waiting for a chance to pop a cap in his behind?
In todays world a LEO can't afford to take the chance.
Say what you will of the officers actions but, again IMO, he was justified with the actions that had already happened.
This officer is supposed to have 14 years of experience - how often do you suppose escaped felons travel with babies in car seats?
You can make all the excuses you want for this guy, but it's clear from the video that he was only interested in putting some citizen in his place for annoying him. His pleasure in making that guy "ride the taser" was all too obvious.
Whether you want to recognize it or not, our society is evolving to cops - with the authority to wreck your life at will or just end it - and us suspects. This isn't the situation our Founding Fathers had in mind, is it?