But I think you should understand that most of us do believe he's capable of shielding his troubled friend rather than doing what's right.
The Catholic Chirch scandals convinced many of us that men who spend their whole lives in service to others and with a healthy fear/understanding of God are still capable of exactly this act or shielding those who perpetrate it.
It's hard to get our minds around something this evil because like the rest of us...you're not screwed up morally. But the evidence and common sense leads most of us to the conclusion that he knew and didn't act so as to shield his friend, his University, his program, and his legacy. In the end, as horrible as it is, it's hhe most likely conclusion.