NCAA has no authority in a legal matter, but they do if it has to do with eligibility. The Alabama OL that I'm sure had his freedom bought with some box seats for the DA at the Alabama-LSU was free and clear, with discipline up to the discretion of Saban. Now, I'm sure if he'd sucked, he would be off the team as a sign of the tight discipline Saban hands out, but like Jimmy Johnson said, different players get different discipline. That is a case where I could see Richt dismissing him from the team, but dismissing a future NFL 1st rounder at left tackle from the team would never even cross Saban's mind.
Miami was stuck because there is a paper trail and people willing to talk about it, just like Ole Miss is stuck with the Tunsil issues. How they make that go away, I don't know. The NCAA could come back and make Miami forfeit games Grace and AQM played this year. There will be zero depth, but it will give the three LB's a lot of experience, anyway. Something tells me he'll be blitzing them a lot, rather than have them run the wrong way.