Revealing mistake: After Number 6 has left the Council Chamber for the first time and is heading home, a white car is seen passing by. (00:09:10)
Continuity mistake: Watch the Butler standing in the background after the committee exits the meeting room. A very bad edit causes him to jump to a different position (a foot further away than he was before) between shots.
Revealing mistake: Number 6 sets up exercise equipment in the woods and performs several athletic stunts on a bar. In close-up, he's bare handed. In long shots, however, the stunt double becomes apparent because he's wearing gloves.
Revealing mistake: The ultra-secret location of The Village is accidentally revealed when Number 6 drinks his tea. While everything in The Village is supposed to bear only its penny farthing logo, the bottom of the tea cup is emblazoned "Portmeirion Pottery." "The Prisoner" was filmed in the Welsh resort village of Portmeirion.
Continuity mistake: An estate car can be seen crossing the background in one scene, as opposed to the village "taxis."
Revealing mistake: At the end of the episode when Number 6 and Number 2 are addressing the crowd, in the long shots facing 6 and 2 you can tell Number 2 has been replaced with a double. (00:47:51)
Visible crew/equipment: When Number 6 is hypnotising Number 86 with his wristwatch, as the camera moves in towards 86, you can see its shadow cast on 6's sleeve. (00:42:39)
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