Free throw violation?

[David B]

Saw a crazy play the other night and have discussed with several other officials and we can't seem to come to a consensus. Thought I'd ask here to see what you guys might have ruled.

Play A1 shooting second of two free throws and is holding the ball when player A2 who is behind the three point line shoves B2 who is beside him and falls into the area which would be a violation.

The referee calls a foul on A2 for pushing B2 but the question is how to administer the play.

In the game I was watching they cleared the lane and let A1 shoot his free throw and then went to the other end and let B2 shoot his free throw since they were in the bonus.

My question is this a violation, should A1 should be able to shoot his second FT?

Also since the ball is live is this a team control foul and there should be no shots by B2 and team B simply gets the ball?

We have discussed other possible rulings what say you guys?

Thanks
David