By unilateral decree...

[Grail]

I see your argument, but the following question (I'll paraphrase) is on the test every year or two:

T/F Team B causes the ball to be OOB when Thrower A1's pass is batted back into A1 before A1 has had a chance to re-enter the court.

We know this is false, as the violation is on A1 and the ball is given to B. So what makes the OP situation any different. B definitely deflected the ball, but it still had front court status. It didn't have back court status until A2 touched it. Who caused the ball to have back court status? A2.

Whether you want to call it or not is your business, but I agree with the interp.