AkronSportsNOW located police reports involving Quincy Diggs twice hitting his ex-girlfriend over the summer. In one, Diggs "threw a plate at [the] victim's head" and in the other he "smacked [the] victim in the face" at a nightclub.
In neither incident was he arrested but in the second one, fellow Zips players Nick Harney and Demetrius Treadwell were listed as witnesses. The report lists the victim as Zaruhi Harutyunyan, a former tennis player who was a three-time MAC Player of the Year and currently enrolled in UA's graduate program.
I agree that it's hard to tell if these violations led to his suspension because many students get into physical fights, but it would make sense in this case to protect the safety of one of their students. At the very least, it didn't help his image.
For what it's worth, I confirmed finding the police reports on the Akron Police Department website.