A person who denies something out of habit, or for the sake of appearances, when in fact it is almost certain that the person did the deed in question. A person who talks about the effects of various drugs, and follows the explanation with "or so I've heard" is shawshank innocent. Inspired by the amazing, award-winning movie (and the even better long story that inspired it) called "The Shawshank Redemption"
Straightedge: Don't smoke weed. It's illegal.
Toker 1: Yeah, but it shouldn't be. It's as effective a pain reliever as some opiates, with far fewer side effects...or so I've heard. I would never do anything illegal.
Toker 2: Shut up homie, you're just shawshank innocent.