This is a bit awful to even think about, but could it be possible that the decision not to just run out the clock could have had something to do with sports betting? (I don't wish to imply that Cristobal himself had money riding on the outcome, but could it be possible that some powerful booster might have pressured him to try to make sure that certain bets in favor of UM would pay off more handsomely?)
I don't gamble, so I don't really know if this scenario is plausible, but logic tells me that there had to have been some tangible gain somewhere that was riding on that choice, and not just the ego boost of winning by a few extra points. (I suppose he could have been thinking of the rankings, but they had no shot at the top 10 for that win, so that wouldn't seem to be compelling enough.)