Having to put your dog down because of the negligence of another dog owner

So me and my wife were just sitting watching stuff and we got a knock on our door and it was one of our neighbors down the hall who had us this piece of paper and was telling us the whole story. We provided whatever information we knew and told them sorry about your dog.

But how fucked up is it that not only did this guy have to have surgery on his hand but also the injuries to the dog were so bad that it had to be put down