Texas did not make the hint of an adjustment in the first half. I thought the reason behind this was to save the alternate strategies for the second half. But when the second half came, they still did not make adjustments till the late 3rd quarter I believe.
And even then, they were insufficient. We know Texas could have stopped that option in its tracks after seeing it at least two or three times. But they didn't.
Thats why I think they were either hung over from Thanksgiving, or simply did not want to bust out the good stuff, and wanted to save it for the Rose Bowl. Texas never really "lost control" of the game, and their composure was never shaken, even when the aggies locked arms and swayed left, right, left, right.
Thus they had no reason to pull all the tricks out of the hat.