I think there might be more going on there. I've watched this thing about 20 times now while freeze framing and it appears that the ball never actually touches the ground. Instead, it appears to be redirected in mid air 12 inches above the ground and in such a way that isn't consistent with it's flight path. The ball's momentum increased, almost as if there was a hole in the texture. Maybe the ball slipped through and was propelled out with more force than it came in with. That kinda stuff happens a lot in games.
Come to think of it, I can't say I've ever seen the ball hit the stick mid flight aside from when it would fly straight into the hole. Are the flagsticks only physical, impactable objects up to a certain vertical limit above which the ball simply passes through it as if it doesn't exist?