Glad all is well with Wishbone. Going back to your original post did you happen to get the badge number of the police officer?.
I would say he was derelict in his duties as he was going to let an injured animal lay at the side of the road after the owners said leave it there. I would have arrested the owners for animal cruelty for not wanting to do anything except leave it there at the side of the road if I was the officer and along with that would have rushed the pup to help.
Let's just hope that the original owner does not want Wishbone back. We all know if they did have him back how he would be taken care of in the future with them.