Advantage/Disadvantage Rebounding

[refnuts]

After A1 releases a shot, Rebounder B2 is displaced by A2 with a forearm to the back while the ball is in flight.

1)Rebound bounces to the other side of the basket, neither B2 or A2 have a play on the ball. Would you call the foul or allow play to contunue because B2 was not put at a disadvantage by A2?

2)Rebound comes out near A2 and B2, and A2 gets rebound. Obviously you must call the foul on A2, but should you have whiststled the play after the displacement or wait to see what happens as a result of the rebound?

3)Should you call the foul if B2 secures rebound anyway dispite displacement?