You can't blame the guy for leaving the scene can you? What would you have done in that situation, stuck around so you can pay 140 dollars because you didn't check your mirrors or split and pay nothing? It's just the path of least resistance. I've been in my friends wagon when he backed into some guys SUV and put a big dent in the side paneling, my friend split of course. I've lifted a couple guys up by misjudging parking lot maneuvers in my F-150, but there was never any real damage done.
Accidents happen, and you know you wouldn't stick around either. And if you really would, then you're more commendable than 90% of the people out there (including me
)