the novel (spoilers)

I just finished the novel and it's remarkable. I think Scott Turow is one of the best writers going today. He really knows his characters.
However, there is one thing about the book that doesn't sit well with me. Erno Edai murdered the three people at the restaurant and framed Gandolph. He'd gotten clean away with it. Collins said he regretted it after he got cancer, and wanted to basically make amends and save Gandolph. That just doesn't sound right to me. I kept expecting another revelation to come about the crime itself. Erno just didn't strike me as the type to really care about something like that, no matter if he was dying or not. Plus, there was the chance the evidence could be construed that Collins was the killer, or at least involved. It just didn't seem right for him to want to risk his nephew's safety when everything would be fine if he just kept quiet. Also, he mentioned his own pension.
That was the only part of the book I found wanting. And I realize without Erno's confession there is no book. I'm just saying within the consistency of Erno's characterization it didn't seem to make sense.