I'm no attorney but will play a member of the jury, here ...
What exactly is there to sue over?
-- Medical expenses? Covered and paid.
-- Loss of income? How can this be proven, at this point in time? Seems to me the only argument could be made if he is still unable to perform due specifically to the long-term, irreversible effects of rhabdo at any level of professional football, permanently. This is something that could not be known until at least next spring, when he would be preparing for a shot at the NFL. How can it be proven that he was ever going to be good enough to play professionally? All present and recent evidence (failure to progress on the depth chart and actually being passed over before the rhabdo occurred) suggests otherwise.
-- Punitive damages? Generally these are awarded due to negligence and / or intent, both of which have been dismissed by independent review.
I'm sure there are plenty of attorneys and court rooms that will entertain a lawsuit but I'm struggling to see the integrity of the case.
*IF* another doctor were to find that permanent damage has occured (say his liver will never recover and never function properly again), there *might* be something be a case for a suit. I would think that they would have to prove that the damage negates the ability to do a job (such as the NFL) that he could have done if the damage hadn't occured (and, of course, he would have to prove that the UofI was responsible for the damage). Tough sell, I would imagine. Then again, there are lawyers that will sue for anything...