re: Why do coaches preach play to the whistle blows....(fumbled punt)

In my day, that would have been looked at far more carefully. It was a fumble.. The moment he secured and tried to advance would have 'negated' the forward progress explained. I caused a safety in college, on an identical play, where I knocked the punt returner back into the endzone [and on the deck].

Michigan's player may have been down before the goal line [knee IIRC] but even their spot looked suspect to me.