Violation? Why??

I still can't believe this happened... but here goes.

Team A on baseline under their basket for a throw in.
Throw in pass deflects off the bottom of the backboard, then passes through the underside of the hoop.

My partner and I conference, he feels violation on A for not passing directly into the court. I agree, violation on A because ball passed thruogh the ring from other side.

Anyone have a clarification for me?