4-2-3:
b. The team last in possession may choose to either put the ball in play where possession was lost or replay the down if, during a down or during a down in which the penalty for a foul is declined, an inadvertent whistle is sounded while the ball is loose following a backward pass, fumble, illegal forward pass or illegal kick.
c. The team in possession may choose to either accept the results of the play at the dead-ball spot or replay the down if, during a down or during a down in which the penalty for a foul is declined, an inadvertent whistle is sounded while the ball is in player possession.
This play is really not a good example to use because there was no IW. But if there had been an IW AFTER the interception and BEFORE the fumble, then (c) would apply. a ball in player possession blown dead. accept tje result of the play (TB), or replay the down.
If the IW occurred AFTER the interception and DURING the fumble, (b) above would apply. a ball fumbled by the team last in possession can take the ball at the spot where possession was lost (EZ for a TB), or replay the down.
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