Basket Interference
 

NFHS Boys Varsity. A1 has the ball in the low post. A1 spins and attempts about a 2 foot shot. B1 comes down the lane and goes up for the block. B1 is late in his block attempt and strikes the backboard very hard as the ball bounces off of the backboard and hits the front of the rim. The striking the backboard makes the rim vibrate and causes the ball to bounce out of the cylinder. B1 was making a legitimate play on the ball and R1 believes A1 would have scored if B1 had not slapped the backboard and caused the ball to come out of the cylinder. Has any rule been violated? Rule number

Nope.

10.4.4 SITUATION:
A1 tries for a goal, and (a) B1 jumps and attempts to block the shot but instead slaps or strikes the backboard and the ball goes into the basket; or (b) B1 vibrates the ring as a result of pulling on the net and the ball does not enter the basket.
RULING: In (a) legal and the basket counts; and (b) a technical foul is charged to B1 and there is no basket.
COMMENT: The purpose of the rule is to penalize intentional contact with the backboard while a shot or try is involved or placing a hand on the backboard to gain an advantage. A player who strikes either backboard so forcefully it cannot be ignored because it is an attempt to draw attention to the player, or a means of venting frustration may be assessed a technical foul pursuant to Rule 10-3-6.

Rule 10.4.4 Neither one of these things happened
B1 vibrates the ring as a result of pulling on the net and the ball does not enter the basket. B1 do not pull on the net

A player who strikes either backboard so forcefully it cannot be ignored because it is an attempt to draw attention to the player, or a means of venting frustration B1 did not attempt to draw attention to himself or was not venting frustration.

Would it still be a T since the ball did not enter the basket?

No. In NFHS play, it is only a technical foul if a player deliberately strikes the backboard. Doing so while legitimately attempting to block a shot is NEVER a technical foul or basket interference.

Note that the NCAA rule is different.

+1. This drives NFHS coaches bananas because they always think there should be something to call, but in reality, given the OP description, there is no call to make.

NCAA passed a rule change about 4 years ago making what was described defensive basket interference. This rule change has not trickled down to high school yet. Personally, I don't think it ever will, though who knows...

He could bring the entire stanchion down with the slap and it still would not be BI.