Now you could say animals are not children. But for some people they are. And there is such a thing as neglecting parental/supervisory duties, which is comparable to neglecting leash laws.
In both cases, what it comes down eventually - in my opinion - is the cruel statement "Dude, your dog/kid ruined my car."
Of course people are attached to their pets, but the emotional attachment isn't legally recognized and doesn't make a pet equal to a child legally
. It's a tough situation. No one is happy about the dog's death, but what can be done? The car is damaged, and leaving it damaged won't bring the dog back. Not paying for the damage won't bring the dog back, either.