[JRutledge]

I do not know what "big displacement" means.

My rule of thumb is anything a player that rebounds was bumped. I consider did they lose the ball? Did they do anything that they would not have done (like fall out of bounds)? Did the player violate their verticality? Were they hit in the head? And I might consider a couple of other things I cannot think of. But if a rebounder comes down under control and maintains control of the ball, I am probably going to not consider any contact a foul.

Peace