Definition of a shot from behind the backboard- High School

[Jack]

Gentlemen,

Another question from a coach.

A player grabs a wide offenside rebound just outside the key close to the baseline.

He turns and from that position shoots and makes a high arching shot.

The referee allowed the basket the other team inbounded the ball. Play continued and then at the next dead ball -perhaps ten seconds later. The opposing coach complained and the reeferee took the points off the board- citing the illegality of shooting from behind the backboard.

Question 1 - what is the criteria for such a call in High School.

Question 2 - once play has continued after the other team inbounded and advanced the ball can the refferee essentially change his mind like that.

regards,

Jack