Actually, now that I think about it, you guys are probably right with regard to the Ray Allen situation; it's a little too hard for him to really "fake" a shot due to the way he naturally shoots.
Interestingly, although Nate also shoots in a very similar way to Ray, I would argue that he could use a pump fake effectively. Here's the difference: people stay down on Ray because they know they're not blocking the shot and at best they'll just be getting a hand in his face. As far as Nate's concerned, though, defenders are more eager to actually try to get up and get a piece of the ball, so they bite more easily. Anybody find this plausible?