You don't really know what happened, but the eventual conclusion that most would take is:
1. he got a passing grade in spite of irregular class attendance. This is highly unlikely, but always seems to be the first place people go because "athletes get treated differently."
or
2. he got a late drop - which some consider "unfair," even in the light of late drops being available to any student for a whole host of reasons (For example, I dropped an entire semester due to depression, well after the drop date)
I would imagine at many or most big sports schools, it is the latter.
Actually, I wouldn't be surprised if it's the latter at UNC too. If so, UNC has done a world-class cover up so far by making it look like the former.
It's possible to be a scholarship athlete and get a real academic degree. I've seen people do it first hand. But it's hard -- you need to start with a decent academic background, and then work your ass off and most likely the social aspect of your college time will suffer.
That being said, even without the best academic background its possible to legitimately graduate if there is institutional support for it. The student might not have the most rigorous undergraduate course work, but they will have earned a degree equivalent to many non-athletes at the school. But for this to happen there needs to be institutional support both inside and outside the athletic department.
What's disturbing to me about UNC, is not just that they knowingly and persistently cheated, but that there behavior was purely and most basely exploitative -- they weren't even pretending to educate these students.