[Mark T. DeNucci, Sr.]

By definition the backboard is considered part of the court, unless a field goal or free throw attempt is involved. In the posted play A1's action was not a field goal attempt. A1's throwing the ball against the backboard and then being the first to touch it was traveling. His action is no different that if he had thrown a pass to A2 and then touched the ball before A2 or any other player had touched the ball, and it does not matter if the ball touched the court (including the backboard) or not before A1 touched the ball the second time.