Here is another situation that prompted a fan/friend to call me last week. I was not working the game but...here it is:
As time runs out A runs ball and is downed close to goal line but doesn't score. foul by B during the live ball. untimed down is ruled. A comes to line, and false starts. 5 yards enforced against A. Even though they false started the untimed down from the previous live ball had not been run yet, so the untimed down is still run after the false start by A. needless to say, A scores, B loses and the fan was a fan of B and wanted to know why A got to run the play even after their false start.
I explained that is was because the false start was a dead ball foul and the untimed down had not yet been run yet...
unless I am missing something had I been the R this is what I would have ruled as well.