Reference for Throwing Ball off Own Backboard

[just another ref]

Originally Posted by Camron Rust

He didn't move his pivot foot while holding the ball. He didn't start a dribble after lifting the pivot foot. He let the ball hit what is treated the same as the floor after throwing the ball into the air...except that it is expressly not considered a dribble.

What part of the travel rule was broken?

4-44-3: After coming to a stop and establishing a pivot foot the pivot foot may be lifted but not returned to the floor before the ball is released on a pass or try for goal .

Throwing the ball against the board in this case, according to you, apparently is neither of these.

4.44.3 C b: A1 throws the ball over the head of B1 and then takes several steps before catching it.
tr
Ruling: Since the ball did not touch the floor, the tossing and subsequent catch is illegal.