Hi Phil,
I mean no offense by this, but I would argue that your dog was not 100% finished. This really has nothing to do with pointing and all to do with steadiness. The dog needs to understand that this is a command. In fact, it should take some time to accomplish. When I say 100% steady, I mean the dog doesn't move; end of story. You should be able to attach a lead to the dog and put decent pressure on him and he will resist.
When I first ask my dog to flush, he doesn't do it. I am asking him to perform an un-natural act. I need to re-enforce it. At first the dog is apprehensive to do it, but after a while, he understands what he is being asked to do.
If anything, I have found this improves the pointing intensity of a dog that lacks. The dog learns there is a chance of him being allowed to go after the bird; which gets them pumped up.