Slapping the backboard ruling

[billyu2]

This play was posted in our area recently: Player A releases the ball on a layup attempt. Player B makes a legal attempt to block the shot but contacts the backboard causing the board and rim to shake altering the flight of the ball. Goaltending, basket interference or technical foul? Local Association A answered no GT or BI but since the flight of the ball was altered it would be a technical citing the second part of rule 10-3-4b. Local Association B answered no GT, BI or T since it was a legit attempt to block and there is no rule that requires us to determine if the ball flight was altered. This play then happened in a game last night and the officials ruled BI because the flight of the ball was altered when the ball touched the shaking backboard. Your thoughts?