I am not sure I understand the positioning of the officials. Please correct me if my assumptions are in correct.
My assumptions are L and T are table side and "rocker" means that A1 has the ball on the C's side of the court above the free throw line extended.
If these assumptions are correct, then T has his back to Team A's bench and L has a good look at Team A's bench in case Coach A requests a timeout.
If Coach A makes a request for a timeout while A1 has player control of the ball, then it does not matter if L's whistle is after A1 releases the ball. Coach A gets his timeout and the field goal attempt does not count. When the official sounds his whistle is not important in this play, what is important is when Coach A requested his timeout.
If Coach A made his request after A1 released his field goal attempt, then the L should have ignored Coach A's request for a timeout.