Last play of the game, 4th down, inadvertant whistle

[kdf5]

If there's an IW during a down or during a down in which the penalty for a foul is declined then you do the following:

Legal forward pass or snap in flight or during a legal kick you replay the down

If ball is loose after a backward pass, fumble illegal forward pass or illegal kick, the team last in possession may choose to put the ball in play where possession was lost or replay the down

If the ball's in player possession that team may choose to accept the play at that spot or replay the down.