I'd pass him right off into someone else's hands.
A friend's brother was taking his girlfriend, who lived around the curve from us, home one night when I was in college and home for the holidays. Our elderly dog, who was going both deaf and blind, was in the road; he tried to swerve but couldn't, and he hit her. He didn't know it was our house, but he still stopped, came to the door, told my dad what had happened, and we were able to take her to the vet. In this case, it wouldn't have made much of a difference in the end whether he had stopped then or come back after he got to his girlfriend's house, but I thought much more highly of him for stopping.