Legal, slapping the backboard is only a T when it is intentional. The player attempted to play the ball therefore did not attempt to intentionally slap the backboard. 10-3-5a
Edit: Check this out it deals with that situation:
http://www.cabocanada.org/interpreta...nterpretations
[Edited by ref18 on Jan 23rd, 2005 at 08:57 PM]