With time winding down and Wisconsin facing a two-point deficit tonight in Tempe, the Badgers attempted to set themselves up for a game-winning field goal attempt. That attempt never came, though whether that's their own fault, the officials', or Arizona State's is still unclear.
One thing is for sure: Wisconsin quarterback Joel Stave did not take the most optimal action in trying to stop the play and set up a spike attempt. Instead of clearly kneeling, Stave simply crouched and set the football down on the ground. While you can see an official waving the play dead (and Stave's knee, at one point, does touch the ground), Arizona State players fell on the ball, wasting several seconds. The umpire then took an additional number of seconds spotting the ball, leaving no time on the clock and the Sun Devils with a stunning victory.
NCAA rules no longer allow quarterbacks to spike the ball with less than three seconds remaining, but if the play had been immediately called dead and the ball spotted they'd have had that much time.
Should Arizona State have been flagged for delay of game? Probably, but it wasn't adequately communicated to them that the play was dead. Everybody shares a bit of blame, and I'm sure we'll hear plenty about who deserves the most over the next few days.