Poi?

[Lotto]

A.R. 22: Before the bonus rule is in effect, B1 fouls A1. The official errs by awarding A1 a one-and-one attempt.
(1) A1 makes the first free-throw try, and the error is then discovered; or
(2) A1 is successful in both free throws and then the official detects the error; or
(3) A1 misses the front end of the one-and-one and the game clock starts, at which time the official detects the error; or
(4) A1 is successful in the first bonus attempt but misses the second free throw and, as a result, the game clock starts and B1 scores a field goal. In each of the four situations, the error shall be called to the attention of the official before or during the first dead ball after the game clock has been properly started.
RULING: Each of the four situations is a correctable error.
(1), (2) and (3) Team A shall be awarded the ball at a designated spot nearest to where the foul occurred. The free throw(s) and activity during it, other than any technical foul or a flagrant 1 or 2 personal foul, shall be canceled. Any points scored, time consumed and additional activity that may occur before the recognition of the error, shall not be nullified.
(4) Team A shall be awarded the ball out of bounds at Team B’s end line, which was the point of interruption, to correct the error. The free throw(s) and activity during it, other than any technical foul or a flagrant 1 or 2 personal foul, shall be canceled. Any points scored, time consumed and additional activity that may occur before the recognition of the error, shall not be nullified.
(Rule 2-12-1.b, 2-12.5 and 2-12.2)

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Your second situation is not covered by this. In this case, you'd give the ball back to B at the designated spot nearest to where B2 was when the whistle was blown.