I had noticed this before, but it was so obvious in a game I played last night. I was Clemson playing against Navy. I wasn't having a great offensive game and i was up 10 - 0 approaching the dreaded 2 minute mark in the first half.
Navy got the ball with just over 2 minutes to play. Ran 2 plays and got 3 yards. Clock goes under 2 minutes. Third and 7 the option gains 5 yards, but... FACEMASK on the defense. First down Navy. Navy proceeds run 4 plays to go about 60 yards for a TD but miss the XP, so now its 10 - 6. I get the ball back with 1:15 or so to go, and hit my WR on a hook route, he breaks a tackle and makes the safety miss an takes it the distance for a 17 - 6 lead with just under a minute to play. So I kick off to Navy, the returner breaks tackle after tackle before I can bring him down just short of midfield. It takes Navy 3 plays to go 55 yards and score again - Score at Halftime 17 - 13. Navy has 0 points in first 11 minutes of the game and 13 points in the last minute.
Second half is much of the same. I don't play great of offense, I add a TD to go up 24 - 13 at the end of the 3rd quarter. With just under 2 minutes, I'm forced to punt the ball to Navy. In pass commit, Dime 3-2-6 cover 4, the Navy WR gets behind my defense for a score. 1 play - 70+ yards TD. 2pt conversion fails, its 24 - 19. I manage to get the onsides kick and kick a FG as time expired for a 27 - 19 win.
In summary, Navy scored all its points in the final 2 minutes of each half, and managed to stay in contention despite being able to muster NO offense for 20 of 24 minutes of gameplay.
Now someone tell me again there's no comeback AI