Well, the dog was a strange dog and it felt threatened. It's actions afterward seem to indicate it was sorry. So I am curious as to whether the dog can be "saved". The obvious question is, were the dog's actions after the bite out of fear of punishment? If so, it should be put down. Perhaps we will never know???

BTW, never put your hand where ANY dog that does not know you cannot see your hand without turning it's head. If you want to befriend ANY dog, offer your hand palm down for sniffing, then pull your hand away and "call" the dog to you. If it doesn't come to you, ignore it and keep an eye on it.