[Ref in PA]

You handled the situation correctly. When the whistle sounded, the ball became dead. A1's subsequent toss at the basket would not have counted. A delay of game warning could have been issued to the shooter for not returning the ball to the administering referee in a timely manner, but personally I would not do that. Coach B sounds as if he wants to whine.

And yes I would tell the table to get their head in the game.