I had an old fat dog who would walk very slowly, so Mom used to walk him without a leash. But he would sometimes walk in the middle of the road. So they were on a walk, and one of our neighbors in an SUV came up and ran him over. After that he said he thought the dog would move out of the way. Mom had to take the dog to the vet who said he was bleeding internally and put him down. I don't think the neighbor felt at all sorry for what he had done.