I guess I messed the part in the story that said Foley was driving drunk.
As a law enforcement officer myself, I will say that the cop is the idiot. Regardless of what you think, even cops have off time, and are not always on duty. In this situation, if I saw a car that I suspected was being driven by a drunk driver, I would have called in for an officer in that jurisdiction, to investigate. I would continue to follow the vehicle, until the unit was in position. I would under no circumstance approach the suspect, without proper uniform or identification, unless I had back up.
Furthermore, from reading the article and seeing the video, This officer was out of his jurisdiction. He is a cop in Coronado, and shot this guy in Poway. If he was on duty, he would have had to call the Poway Police for assistance, and should have done the same while off duty.
I would hate to be this officer, he is in deep doo doo whether the shooting was justified or not.