If there is an inadvertent whistle on the play , there would be an untimed down regardless of the team in possession's choice (3-3-3c). Several years ago, the rule read : untimed down ONLY IF the down is replayed after an inadverent whistle. Then this happened : In a mid-west state championship game, B intercepted a pass and returned for a TD --
however during the return
an egar tweeter blew his whistle - the first half had ended on the play
.. A delima.....B didn't want to replay the down as that would give the ball back to A. Taking the ball at the spot of the tweet
ended the half. Results were the rule as is today, an untimed down if an IW during the last timed down. (6-1,4-2)