Arch just played like he had a bundle of nerves. The longer the game went on without a break, the tighter he got bound. It'd be nice to say he had ice water in his veins and shrugged off the pressure, but that wasn't the truth. He didn't want to make a mistake, so he overthought, the game sped up, and he lost muscle memory. The INT came when he got worried about the pressure and "tried to make something happen".
tOSU got their first TD when the Longhorn defense committed two drive extending penalties. They got the breaks, clustered them, and took advantage. Their own newbie QB made a terrible throw to a wide open WR who managed to play the ball off his own thigh for a score.
Now they're voted #1 and Texas isn't. Fair enough, but don't pretend like there's a gulf of difference.