I think about how it got out in the open though.What i mean is the truth behind Fredo's death.Even Mary and Vincent know about it,Kay says"Anthony knows you killed Fredo".How did it get out in the open?

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