Free Throw violation?

[JWC]

I am in my 3rd year. Had this happen last night.

Boys Freshman 3 seconds left. Team behind shooting the tail end of 2 shot free throw. Shooter throws the ball hard at the basket. Ball hits the rim then the backboard and bounces back to the shooter. I am under the basket. The trail calls a violation saying you must attempt to make the shot. I looked and still can't find it in the book. Any thoughts?

JWC