Welcome to our forum, Ref4bills, I hope you find it both enjoyable and useful. A similar play to yours caused a rule change several years ago as the prior rule allowed an untimed down ONLY IF the down was replayed after an inadvertent whistle. As I recall.....
Late in first half, state championship, mid-western state :
(1) B intercepts A's pass;
(2) eager tweeter tweets;
(3) B returns for TD;
(4) IW cancels that;
(5) clock reads 0:00;
(6) to get an untimed down then, B would need to give the ball back to A;
(7) half ends;
(8) clamor to change rule.
Rule changed, today B would get an untimed down where the ball was then the tweeter tweeted.
Remember, guys, to beanbag where the runner is when the whistle sounds.
(8)