The Deadball foul was before the before the ball was spotted "ready for play" is why it was 1st and 10. Dead ball foul after the ball is spotted for play is where you could have a first and more than 10. OR obviously if a first down live ball foul is accepted by the defense where you replay the...
I saw the game too. 0.00 was on the scoreboard. A foul after time expired does not extend the game. If the penalty was sooner or the clock operater a little quicker on the stop watch there would have been one more play after a 5 yrd walk off.
Great game by both teams!