Maybe a new question for the Back Court Violation Quiz

[Ref in PA]

In our chapter meeting last night, this situation was presented:

A1 begins to take a shot for goal at the top of the key. A) Before A1 releases the ball, or B) After A1 releases the ball, B1 swats the ball from behind and the ball bounces off of A2 who is in front court and bounces into back court where A3 retrieves the ball. Violation or Not? Why?