Back Court?

[JB]

My partner last night gave me this scenario which he had earlier in the week.

A1 is just over the division line and has established himself in the front court. A1 is trapped by B1 and B2. A1 throws the ball off of B1 and steps back into the back court where he now has player location. The ball returns to A1 without ever touching the floor. While in the air the ball has front court location.

When A1 catches the ball is it a violation?

My interpretation: Once B1 touches the ball anyone can recover in the back court. The fact that the ball is in the air has nothing to do with this situation.