1) Had the attacker not forgotten to put his car in park, he may have gotten the jump on the cop. The extra commotion gave the officer time to realize something wasn't right here.
2) The cop handled the attack pretty well I thought. Immediately tried to put distance between himself and the assailant, and it looked like he put 4 of 6 shots center mass maybe?
3) I'm assuming the kid on the traffic stop got out of his ticket. Lucky day for him guess, other than having to witness what transpired.