Under NFL rules, there wouldn't have been anything to debate. Under NCAA rules, one of the most controversial plays in College Football Playoff history was born.
Trailing 14-3 in the Fiesta Bowl, Michigan quarterback J.J. McCarthy seemingly connected for a 51-yard touchdown with wide receiver Roman Wilson. Instead, the on-field ruling was overturned, and Wilson was ruled as down at the one-yard line:
A play later, running back Kalel Mullings fumbled the ball and TCU recovered.
Mind you, Wilson was never touched by a defender. In the NFL, even if it was determined Wilson caught the ball at the one-yard line, he would have been able to roll into the end zone for a touchdown. But in college, a defender doesn't have to touch you to be down once you hit the ground.
And so, the debate became about whether Wilson was actually down at the one-yard line, and whether there was enough evidence to overturn the on-field call of a touchdown: