Game is under NFHS rules
Player A2 steals the ball from B1 in B's baclcourt and heads to the rim for a lay up - B1 truns and bolts after A2 and can not get to the layup and while the ball is on the cylinder B1 slaps the backboard, below the rim, hard enough to visibly vibrate the board and the ball does not go in.
please make your call and back it up with rules
feel free to add NCAA also.