Also note that when Fredo's playing dumb, you see a genuine smile on Michael's face, as if for the moment, he didn't think it was Fredo who was the traitor.

The hero and the coward both feel the same thing, but the hero uses his fear, projects it onto his opponent, while the coward runs. It's the same thing, fear, but it's what you do with it that matters. Cus D'Amato