Gold Is Where You Leave It - S1-E19
Audio problem: After the Apaches rescue Blue, Buck signs to their leader and says, "Vaya con Dios to you too, brother." But his lips never move.
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: Apparently there was a problem with the sound recording during a scene of Ben Cartwright speaking to his son Adam while standing by the chuck wagon. One of Ben's lines was dubbed in by someone else whose voice was higher-pitched and less gruff than that of actor Lorne Greene.
Audio problem: Just before Dorothy has her operation, Mike is seated at her desk looking through her medical books. Sully pays a visit to comfort her. During their moment, you can hear slight foot shuffling from the camera crew in the foreground - which is not coming from the outside. Also, you hear a slight grunting during a pause in their conversation.
The Campout - S2-E5
Audio problem: When Laura and Nellie are on the branch going down the rapids they can be heard talking, but their mouths either don't match with what they are saying or don't move at all.
The Night of the Cut-Throats - S3-E11
Audio problem: Arte's hand and finger movements on the saloon piano don't even begin to match the notes actually being played. (00:07:30)