The Men That Corrupted Hadleyburg - S2-E18
Audio problem: Final sound edits were incomplete on this episode when star Pete Duel committed suicide, so his dialogue is "looped" by another actor in several places. Though it's an excellent imitation, it is most noticeably not Duel's voice when Heyes and Curry are waiting for Harry in the opening scene, at the campfire with the Tapscotts, and when Harry tells them about the trial's outcome.
Audio problem: Just before Curry shoots the rattlesnake, Heyes says, "Don't anybody move." But his lips don't move when he says this. (00:11:20)