As it stands right now, the most concrete evidence of Te'o's complicity isn't concrete at all. It exists in the argument that nobody could be that naive or gullible for that long - therefore, he must have been in on it.
I think this is specious reasoning, however - and I think I can demonstrate how. Imagine that Manti Te'o wasn't the starting MLB for the University of Notre Dame, as well as the most decorated defensive player in the history of college football. Imagine he was just some guy we had never heard until news of this hoax broke. Would we be so quick to assume complicity in that case? If they guy had been living in a trailer park instead of Dillon Hall at Notre Dame, would we assume his guilt a little less quickly?
If it appears I'm making an overtly classist argument, that's part of my point. I think people are reflexively assuming a level of intelligence on Te'o that could easily be overestimated, and at any rate, should be demonstrated rather than affirmed. Think of what kind of factory schools become when sports like football and basketball are concerned. It's almost always taken as a matter of certain fact that big time college athletes are gaming the system in some way. Not going to classes, not taking tests, not writing papers. In Peyton Manning's second pro season, Sports Illustrated published an article detailing, among other things - just what an idiot he was - not knowing how to open a can of soup, or even heat one up. In a world where athletic prowess is so prized, it wouldn't shock me to see normal critical thinking skills given less of an emphasis.
To me, the best argument for Te'o's basic innocence is the currently ticking clock. It's been 5 days since this story broke. Te'o's story is that he was duped by Ronaiah Tuiasosopo with the help of at least one or two other people. All we've heard from Tuisasosopo (through family surrogates) is that his family is meeting later this week just to discuss how they should address his role in the hoax. Just to discuss that. In the meantime, Te'o will be doing an on-camera interview with Katie Couric where he's guaranteed to repeat (if not offer more compelling evidence) that RT was the hoax's mastermind, and that he had no part in executing it.
If Te'o was complicit in the hoax, and I'm Ronaiah Tuiasosopo, I don't see any percentage in sitting on my hands and letting Te'o do all the talking. He's already outed me, trying to shred whatever reputation I ever had. I'm certain to have at least as much (if not more) proof of Te'o's complicity (emails, texts, etc.) as Te'o claims to have of his innocence. If I can prove his guilt, nobody's going to write songs about me, but I won't come out of this shit-storm nearly as bad-off as Te'o will.
Lying about Te'o's complicity probably opens RT up to defamation lawsuit. But saying nothing for this long gives us a different picture of who's got something to feel guilty about, IMO.