FWIW .. The standby "expert official" on the broadcast said there has to be at least 3 seconds remaining to spike it and still have time on the clock. Not sure why that is, but that is what he said.
It’s true, there’s a specific NCAA rule about the clock and spiking the ball. It was quoted on page 105 of this thread.
Without the injury stopping the clock, it’s possible that the refs would have started the game clock after moving the chains, and Iowa could have hiked the ball with 2 on the clock, spiked it quickly while the clock still said 1, and then had the B1G refs explain why the 1 second had to be taken away by rule and the game could have literally ended with 1 second on the clock. Of course, that would have been the mystery second from the Western Mich game, and the college football world would have been outraged.