Emily -

I'm really sorry about this situation. I know its hard on you too even though it isn't your dog.

Another option would be to have the behaviorist call the GR Rescue and discuss the dog with them, making sure he won't be put to sleep. If you're uncomfortable with that, I would just break contract and surrender him to another rescue. They will have to lie though and not say a word about the rescue they got him from to the other rescue. Generally if a shelter or rescue receives a dog from another shelter/rescue, they will contact them and let them know they have one of their dogs returned to them.

I hope I'm mkaing sense. I just woke up and can't think straight yet.

Good luck to you and your neighbors