I've noticed that Hufflepuff sometimes pre-rolled >10 times between "main bets". Maybe he has a really good strategy that was painstakingly developed using hardcore probability statistics.
He probably figured a way to determine when the middle part that loses either way, above 33.0 and below 66.99, has passed its cycle and just bounce between <33.0 and >66.99 depending which one is going into positive variance.
No. Unless he knows the server seed it's just dumb luck.