Reports I've read say that the play should have been called dead as soon as the Kent player recovered it. Is this a rule change? Because I remember Julian Posey scoring a touchdown off a muffed punt against Wofford.
You can't advance an onside kick, I know that much. I'm pretty sure you can't advance a muffed punt either. However, if it is fumbled after the player makes a "football move" or whatever they call it, I believe it can be advanced.