CU had 12 men on the field on the 4th and 1 punt. They had a guy that was 3-4 yards from the sideline when the ball was snapped, but it is my understanding that none of the TV angles actually showed this. This would have given the Big Red a 1st down and a chance to eat more time off the clock. From my seat in the North Endzone it was pretty clear that CU had to many guys on the field. He ran right by the line judge as well.
I didn't know you could actually challenge this play.