Stoops and OU very well may have mishandled this situation on the side of leniency. But as I said in another thread, I don't know the full extent of what OSU did, or did not do, with Mixon.
The NCAA released its grip on PSU because in the end it was actually a legal issue and not a NCAA issue. As screwed up as the NCAA can be I think they realize there is no cookie-cutter solution to be imposed on schools for using their own judgment, for better or worse, in the situations in which student athletes violate the law.
Even judges in a court room will consider various aspects of different cases that look very similar to us on the outside and then render different judgments in those cases in terms of what is required of the guilty party. I've actually sat in courtrooms watching judges wrestle with the ins and outs of a particular case in an effort to administer justice and also set forth a specific course of action for a guilty individual in which the judge creates an opportunity for the guilty party to make restitution or redeem themselves, so to speak.
I'm not going to argue endlessly about Mixon. What he did was pathetic and, in my opinion, required a very serious response from OU.
One of the differences between an intercollegiate athletic program and having an employment contract is that your employer assumes you are a competent adult. Intercollegiate programs, especially these days, see themselves, at least in part, as an entity that helps develop young athletes, even troubled young athletes, toward becoming an adult. And sometimes that is just a can of worms waiting to be opened.