Ok, maybe some of you armchair doctors need some schooling. Most of us have stubbed their toe, or hit their finger with a hammer in their lifetime I assume. Now, while it may hurt a bit for the rest of the day, the pain slowly starts to subside after the initial injury. I agree that it will hurt like a b*%ch initially, but after a few minutes, and some heavy cursing, you are able to function again.
I would assume the same would be true with your shoulder dislocating/separating although it would be on a higher level of pain. My guess is he had several hours where the pain went down on its own, and may have even taken some advil or whatever duck and run (and you other clowns) takes for his menstral cramping.