This was one of the more embarrassing non-fatal nypd moments i can remember. There has been public outrage. Both bloomberg and the police commissioner condemned the officer immediately after seeing the video. Personally, since he was a rookie, my guess is he was doing it at the behest or the other officers there on duty, and they should share any responsibility for the actions.
I honestly do not believe, union or no, that this person will be associated with the nypd 6 months from now. Whether he serves jail time is different story.