Was he handfed? If so, I'd go to another avian vet. Are you positive the vet you went to is a certified Avian vet? There was an anecdote in Guide to a Well Behaved Parrot (I think) about a cockatoo with a leg problem. He was obviously in love with his family, but nobody could ever touch him. They went to another vet, who diagnosed the Too with a leg problem and they fixed it. After that, the Too was back to 'normal' and he became an instant cuddlebug.