Under the Front

[mick]

This has always been a tough call for me.

F (front) is in front of B (back).
F and B are in the paint.
A shot goes up and rebounds toward F and B.
B jumps first, and high, and grabs the ball, while legally reaching over F's back, head and shoulders.
F jumps late, but very vertically, and reaches the ball after B, whose outstretched hands, over F, still have the ball.
There is contact on B's arms as F reaches for the ball.
The contact causes the ball to be released, indicating that there was sufficient contact.

The safe call is a no call.
What is the proper call?

mick