This is why I said earlier in this thread that HR for Husker Athletics is not raising enough red flags, or else they are and the administration is overlooking it. If Frost had issues with drinking and was missing visits for key recruits, that is something that in most organizations would result in immediate termination (if it's impacting job performance). I cannot imagine these habits just started late in his 4th season too and it explains a lot for why this team continued to lose games.
As for Joseph, I agree with you that his past misconduct at a minimum should have caused pause in bringing him on as a coach, and if anybody in HR or the athletic administration knew the full story, it likely would have meant passing on him taking over as interim HC.