How do your Correct the error

[TimTaylor]

OK, let's look at this another way. This wasn't a 1+1 situation as described in BillyMac's case reference regarding incorrect instructions from an official on a 1+1 - not even remotely close.

1. Per the OP's situation as described, A1 was awarded 2 free throws.

2. Per 7-2-a, the ball becomes dead when it is apparent that a free throw will not be successful on a free throw which is to be followed by another free throw. It's automatically dead - there is nothing that requires an official's whistle.

3. Now let's look at 5-1: A goal is made when a live ball enters the basket from above and remains in or passes through.

As the ball was immediately dead after A1's miss on the first FT attempt per 7-2-a, B1 can't possibly score because it is not a goal per 5-1.

The correct ruling is to disallow/cancel the "goal" by B1 and line everyone up for A1's 2nd attempt.