[Husker] Question

[Roger Lohr]

I haven't read all posts since yesterday's game.  So, if I missed what I am 
about to ask, I apologize...

In the 4th qtr. yesterday, NU was lined up to punt.  The play clock showed 
17sec. and was running.  The ref stood over the ball and permitted MU to 
come from the sideline and line up.

QUESTION:  Why, with the play clock (25 second clock) running, couldn't NU 
snap the ball and punt it even if MU hadn't lined up?

Thank you,
Roger Lohr-Mpls