I'm no expert but I watched them pretty close. My gut feel is that they were not up for Buff. Minn was not sloppy their first game, instead they looked rock solid. In this game a couple of turnovers early and wham, they're behind by 17! By the time Minn woke up they seem befuddled, didn't know what to do being so far behind. At the start of the 4th quarter, watching them trying to come from behind seemed like watching somebody run in molasses. You knew at that point they just couldn't do it, they were cooked.
If that were Montana or Brady instead of Cousins I'd still be scared and thought they could easily come back. With Cousins they look plain, a little slow, and incapable of busting you. I thought to myself, "they paid what for this guy?" He's not bad, he's good, but he didn't look like a top tier QB.