Walter Uhler provides an in depth analysys of Paterno's role during all the events leading up to the scandal.
Recommend reading both parts 1 & 2.
Here's an excerpt from his conclusions:
"Consequently, the evidence available to us thus far not only clears Paterno of any suspicion that he engaged in a cover-up -- an extremely far-fetched suspicion, in the first place -- but also that Paterno earned praise for performing his legal duty. Arguably, by insisting that Schultz be brought in, Paterno went beyond his legal obligation. "