I am not trying to be a wiseguy here, just asking an honest question. Assuming they beat A&M, the margin of victory might go an awful long way towards influencing where they stand in the polls which will determine if they go to the Big XII Championship, which will determine if they go to the BCS Championship. Were those same circumstances in place for that game against KU you have mentioned here? Or was it just another game?
Some time ago (I want to say about 5 years, but I may be wrong) the powers-that-be at the BCS wanted to try to discourage teams from running up the score, so they made a rule that the computer polls cannot use margin of victory as a factor in determining standings. As far as the computers are concerned, a win is a win and a loss is a loss, no matter by how many points.
But, needless to say, human beings are slightly less rational than computers. Every voter is different and there's no doubt they will be influenced by close victories versus decisive victories. If Texas wins by 13 and OU wins by 45, it could seriously hurt Texas.