I just checked it and the clock did run (almost) continuously in the 4th quarter, but not before.
Since both teams wanted out of there in the 4th quarter (and before) it didn't make a huge difference. OU threw zero passes and had zero plays go out of bounds in the 4th. We had zero plays go out of bounds, only threw one pass, and had one punt.
The pass from Long was incomplete with 4:38 to go and the clock stopped shortly, then was running before the next snap for a loss of about 32 seconds. Two plays later we punted. When OU snapped it for their first down following the punt, the clock was about 29 seconds off from where it should have been.
So the clock stopped once in the 4th quarter for injury, once for flag, and twice for first downs until the ball was spotted (one coincided with the stoppage for penalty). The clock was not stopped for one other first down or for the two plays mentioned above, so the game was probably 65 or 70 seconds shorter than it should have been.