Laziness, rudeness, mobility problems, being fat....
Why did I say people with mobility problems? Because they don't always park in the handicapped spaces and I've seen more than one old man with a cane push the car door into the adjacent car to using it as leverage to ease themselves into the car seat. Same thign when they open it. Why did i say fat people? Because they are too fat to squeeze through the door and lots of people would be too lazy to repark if they can't get out without hitting the other car. I've also seen that a dozen or three times.
I'm just thinking logistically.
I'd stay right there, check for damage and if there is any, get his license plate number, and call the cops. (if I was a woman, as myself I'd be in his face immediately but still take down the license plate)
I wouldn't care if my car was a piece of garbage, I'd still ruin his day.