[Ref in PA]

JR has it right. It is in the rule book in plain black and white.

For those who do not want to read the book

6-7 DEAD BALL "The ball becomes dead or remains dead when:
Art. 6 ... Time expires for a quarter or extra period (see exception a below)
Art. 7 ... A foul, other than player- or team-control occurs (see exceptions a,b,c below)

EXCEPTION: The ball does not become dead until the try or tap ends, or until the airborn shooter returns to the floor, when:
a. Article 5, 6, or 7 occurs while a try or tap for a field goal is in flight.
b. Article 5 or 7 occurs while a try for a free throw is in flight.
c. Article 7 occurs by any opponent of a player who has started a try or tap for goal (is in the act of shooting) before the foul occurred, provided time did not expire before the ball was in flight. The trying motion must be continuous and begins after the ball comes to rest in the player's hand(s) on a try or touches the hand(s) on a tap, and is completed when the ball is clearly in glight. The trying motion may include arm, foot or body movements used by the player when throwing the ball at his/her basket."

The here is clearly stating that if a foul occurs, whistle, then buzzer, then shot that the ball will be considered a dead ball. Penalize the foul, but you cannot count the basket. The only exception to this would be 5-10-1 where the official has definite knowledge of the time. That states:

"The referee may correct an obvious mistake by the timer to start or stop the clock properly only when he/she has definite information to the time involved. The exact time observed by the official may be placed on the clock."

In this case the official is saying the quarter did not end, time is being place back on the clock, therefore a made basket after the horn (provided it was continuous motion) would be counted. Without that exact knowledge of the time, a made basket is waived off, and the FTs will end the period.