As stated previously, the specifics of the crime, and who is culpable, really isn't the point.
As OSU employees with standard Title IX wording in their contracts, Urban and his wife both are designated mandatory reporters of any applicable instance of abuse that involves employees, regardless of where the incident occurred.
At this point, unless she has proof that she did report, his wife has essentially no ground to stand upon. She almost certainly will be terminated "for cause."
The question is whether there is any evidence that Urban was aware, and whether she will be completely forthright or take an arrow. It's pretty obvious that in all likelihood, Urban was aware. If the investigators determine that there is direct evidence, he also will be terminated "for cause," and his contract will become null and void.
My personal guess is that his wife will be terminated and that he will be allowed to resign "without cause," thereby maintaining eligibility for his buyout. OSU will see that as a way of placating him and saving embarrassment for the university. If they make a case "for cause," and he fights the termination, it could get ugly and drag on, and, that's the last thing the regents want.