Yeah, the penalty was because the center snapped the ball before the ref blew the whistle to do so (the clock was going to run immediately and only had :01 remaining). So it was a 5 yard penalty and when they restarted for the kick after that the center wasn't ready and the clock expired before he snapped the ball.
It was confusing in the stands but funny afterward to go back and listen to the CU radio team and the ISU radio team cover it. The CU guys are clueless and going completely ape-chit while John and Eric are able to figure out what exactly is going on right as it happens.
John Walters actually called the the end of the '07 Coloardo game correctly as the play was actually happening.