It was definitely a bad hit. It probably should have been an upheld targeting call. It wasn’t Regardless, it looks like David Blough’s season is done per Gold and Black Illustrated:
Blough suffered a significant injury to his right leg in the fourth quarter and had to be carted off the field and into an ambulance. His junior season is over, with Purdue (4-5) still harboring hopes of a bowl berth. Now, the Boilermakers will have to reach those recently rare heights without their starting quarterback.
This isn’t a surprise, because according to reports Blough’s foot was pointing a way that a foot should not.