When my car hits something, anything, I notice that it has hit something, and if I am not crippled from the impact, I often stop the car, and see if there was serious damage to it, or whatever it was that I hit. Damages to your car from an impact can be worsened if you keep it running. Additionally, the fact that I did hit something in the dark is a good call to me that I really don’t know what it was or how much it could hurt me. I hoped that I didn’t hit something alive, but I couldn’t initially know when I was in the nighttime conditions, and the object came right up fast with the speed of the car.
Even if this person wasn’t unselfish, he could have at least, assuming poor visibility, tried to check about his own car.
I’m very much like you when it comes to hitting things, but a lot of people are not. Not saying the drivers innocently did not know they hit something. I’m just saying it really is possible.