On the (almost) defining fourth down

I noticed this in real time but just came across it again while rewatching the game. This is the potentially game-defining fourth down play that Northwestern converted (barely). It was 4th and 1, and Northwestern ran out a three-wide set after motioning Venric Mark out of the backfield. Look at how Michigan is aligned:

Michigan is in cover-zero man coverage. They have effectively eight defenders in the box against Northwestern's seven blockers and one ball carrier. I understand the fear of putting the ball in the air here, but Michigan is basically not covering the slot receiver. That's about a 15-foot throw and a guaranteed first down, and potentially a lot more if the slot receiver can make Kovacs miss in space. Obviously Northwestern is happy with the way the play ended, but it was their own stupidity that they almost didn't reach the first down.

The reason I point this out is that if Michigan tries this against Ohio State, they're giving up a lot more than a barely reached first down.