Alabama did actually shoot themselves in the foot with turnovers and a couple penalties. That's their problem and it doesn't make Texas's victory less impressive or underserved in any way; but you can't have watched that game and say it couldn't have been different if Milroe doesn't throw it right to the white jersey on his own side of the field, twice, or if Alabama doesn't negate scores with dumb penalties. The fall off was a national media narrative talking on it because it was spicy, but it was obvious then that Alabama would still be at least a 10-2 type team and probably win the west. Beating Georgia was really the only surprising thing about the rest of their season, and Milroe was the same inconsistent QB then as he was in September. Milroe giveth and tooketh away against Texas, Georgia, and everywhere in between.
You did not get that impression in the Texas-Michigan game. Yes Michigan committed some unforced errors - the Loveland freak fumble stands out in my mind - but not doing that would have only delayed the inevitable. That Michigan team was simply not beating that Texas team the way the latter played. Two fundamentally different situations, IMO.