I was thinking about this some more. I'm really not much of a retriever trainer, but I'm a pretty good dog trainer. There is a tendency in all aspects of dog training to think that you can "correct" that which has not been taught. (Maybe y'all ought to go get your Dead Horse Society mugs now....) You have to teach the dog not only what he's expected, but also what the correction means and how to avoid it, whether it's pet dog training, obedience training, or whatever.
You can light a dog up light a Christmas tree for refusing a recall, but if he hasn't been taught what the stim means, he's more likely to head for the hills than to come to you. That isn't a "correction," because it doesn't make the dog correct. It's not even punishment, because it doesn't decrease the incidence of the dog not coming to you. It's a reflection of the handler's lack of knowledge and inability to handle frustration. It's just abuse.
Like Chris, I don't mean to seem harsh, but "The dog has not been forced back to the pile, yet but if it keeps this up, he will be" sounds more like revenge than dog training. It's meant to be instructive, and it's important to maintain the calm, objective demeanor of a teacher. Please don't think of it as something to threaten the dog with, but look at it as a way to help him out of his (and your) jam. He needs to be taught a lesson (or some lessons) but he doesn't need to be Taught A Lesson. If it's approached that way, you may not be teaching the lesson that you're trying to teach.