This goes against the laws of physics. But if I were to play devils advocate I would say. Practice makes perfect. He likes rollers so he rides faster on rollers, If he got used to the flats he would be MUCH faster on the flats.
Once on a group ride this guy who is a mountain biker would pull away on the uphill and drop back on the down hill. At least 2 times I watched him slow down after cresting the rollers.