This weekend I was at a college game and the crew had an IW after a kick try was blocked. What is the proper enforcement in the following scenarios?

A) IW occurs before B recovers the ball.
B) IW occurs while B has recovered the ball and is running towards A's end zone.

The whistle was blown before B recovered the ball and the crew basically ignored the whistle and A kicked off. The try was not replayed.

Thanks.

(NFHS)
If the whistle is during a legal kick the down shall be replayed, if the whistle occurs while the ball is in player possesion, that team may chose to accept the play at that spot or replay the down.

Not sure of NCAAA rulings.

NCAA IW on a try down:
Prior to team-B possession, the down should be replayed.
After Team-B possession, (or in extra periods) the TRY is over (or extra period series is ended).

Covered in rule 4

REPLY: But remember that in NFHS, the try is over and the ball is dead once it is apparent that the kick has failed (except for the Oregon experiment this season). So in the play as originally posted, there was no inadvertent whistle according NF rules.