What was he doing there?
Apparently this parking lot at 2am was not a real safe place to be. I suppose you think the cop should have just driven away, huh?
Trying to play this scenario out in my mind, the thing that bothers me is that if this cop really had suspicions about this person, he should not have approached the vehicle as he did. He either believed it was a routine motor vehicle matter (I doubt it.) or he was just trying to roust a kid (my money is on this one.) or he is a dumb rookie who stupidly placed his life on the line (obviously not, though he acted like it).
At this time of night in a bad neighborhood and I have real suspicions, I’d follow the protocol for a felony stop and get backup first.