I don't compare this to the Katoa situation. I compare it to the Kaufusi situation in Utah. As UBT points out, the kid wasn't enrolled at OU at the time. Similarly, Kaufusi wasn't at Utah at the time when something similar (albeit probably more severe, but he wasn't charged with a crime) happened. Utah chose to rescind it's scholarship offer. OU, when faced with a similar dilema, chose to honor it's offer.
The CU situation with Katoa is quite different, so claiming situational ethics is inappropriate. Katoa was already here, already on scholarship, and had to go through the judicial system and then deal with the University disciplinary process. At the end of the day, Katoa was suspended for what amounts to a year. If anything, Katoa got a much stiffer penalty.
OU is free to conduct its affairs the way it sees fit. I don't think thier decision in this matter reflects positively on the University. For the kids sake, I hope he gets his stuff together and becomes a contributing member of the campus. That would be best for everybody involved. The perception, though, is that OU is willing to overlook these kinds of indiscretions so long as the kid can perform on the football field. That's going to be a hard reputation to shed.