Mary, thank you for sharing the story of your friend and for speaking in plain English which I didn't do. I agree with every word you said.He owns a dangerous dog....
Please do not shift the responsibility back to rescue....
Euthanize the dog...
There is no rehabbing a dog that will bite to the bone....and if the dog goes back and they rehome him and he kills or maims someone else - he will have that on his heart forever.
The best that a rescue can offer is a life of social isolation....and I truly believe that there are fates worse then a painless death.
This has happened to a dear friend within the past year...the got a dog from a rescue with a history of 'nipping' - This was a giant breed that proceeded to launch himself at an adult guest that entered their home...biting through her clothing and sending her to the Emergency Room. It tore their family apart the attack happened in front of one of their children...but ultimately the mom in the family stepped up to the plate and euthanized the dog.
Sometimes owning a real live animal that has the ability to inflict so much harm carries enormous responsibility and that responsibility can cause great heartache.
I pray for your sons healing...hand injuries are so scary and I can only imagine how terrifying for an artist.