I find it hard to believe you would not take 2 vet's recommendation but look for advice on a forum. We are all just pet owners and some breeders as well. That could never take precedence over 2 vets who have had the dog right in front of them to examine. I know this must be a very dificult decision but I would put the dog's health first and do as the vet's recommend.
I would also like to hear how a horrible accident like this could occur and you not notice? I just cannot imagine how it physically could happen. Even so, it must have taken quite some time.