Body Displacement

[alfreedog]

Here is a question and a situation that happens often, just want to get everyone's opinion on how they see this play.

A1 is going up for a lay up and B1 is trailing the play, as A1 places the ball on the backboard B1 blocks the shot but in turn makes body contact with A1 and displaces his body so he in turns hits the floor. Foul or incidental contact?

IMHO This is a game situation call, in some games I have called this a foul and in others I haven't. It all depends if I am at the L or the T or C. At the L I am looking for the body contact not at the shot at the T and C I am focus on the release point showing a good block. I'm listening!