Foul after the last buzzer

[BillyMac]

6-7: 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 occurs (see exceptions a, b and c below).
EXCEPTION: The ball does not become dead until the try or tap ends, or until the airborne 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.
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.

I think that this citation has everything that I need; time expires, foul occurs, try in flight, airborne shooter, returns to floor. I just need to think my way around the several "or's" to fully understand it. Help would be appreciated.

Here's the situation again, with my notes in parentheses: Shooter becomes airborne, ball is released on a try, horn sounds after release (horn doesn't end period because ball is still in flight), ball is blocked by defender into the bleachers, making it definite it will not go in (one definition of the end of a try, since ball is not in flight anymore, maybe the period ends here), airborne shooter is then fouled, not intentional or flagrant, by a secondary defender before landing (the before landing makes this a player in the act of shooting, so maybe the period doesn't end until the player lands).

There must be a simple answer to this just staring me in the face? I must be over-complicating this. Does the horn and certainty of an unsuccessful try end the period, or does the period not end until the airborne shooter lands?

When does the damn period end? Someone please put me out of my misery. I wish I had never brought this up and had just answered christianH's question.