Oh, and I know a really sad story about a golden retriever. He was a sweet dog. He was a huge retriever. He was turned into a local shelter because he had bitten his owner's hand. The doc at the emergency room said it was the worst dog bite he had ever seen.
The dog was taken in by a no-kill shelter and sent to live with a local trainer who uses only positive methods and who has had a ton of success with rehabilitating dogs. After 6 months, he attacked and bit her. He's since been put down.
I'm not saying another trainer might have had different results. But, I'm saying I think there is room to believe that no one method or type of training is perfect.
jmo