The Girl Who Was Death - S1-E15
Audio problem: For some reason, "Londonderry Air" was dubbed over the original song being performed by the actors/singers. Their lips aren't moving in sync with the words at all.
Do Not Forsake Me Oh My Darling - S1-E13
Audio problem: When Number 6 tells the Kandersfeld waiter that he took some photographs, we hear his words, but his mouth doesn't move.
Free for All - S1-E4
Audio problem: During the campaign, the marching band is striking up a lively tune, and the bass drummer is pounding away on his drum - but there's no drum beat in the sound mix.
Audio problem: Number 48 is still singing when he's carried out near the end - his lips are moving but we don't hear anything. A few shots later, we can hear him again, but his lips aren't moving in sync with the sound.
Audio problem: During a fight with Number 6, one of the Village keepers falls from the bell tower. His fall terminates in the sound effect of a loud splash - but the bell tower isn't anywhere near any water.
Audio problem: During the scene when Number 6 warns Number 2 of a potential assassination attempt on him Number 2 brushes it off and says "it's the little watchmaker that concerns you" but his mouth does not match this. (00:29:43)
Chosen answer: We're led to believe Rover is some kind of robot in the series. According to books on the show, Patrick McGoohan was looking for an unusual guardian for the Village, looked up at the sky, and saw a weather balloon, which was what Rover was.
Captain Defenestrator