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.
Factual error: Several of the chess moves called out over the loudspeaker are not possible with the players in their current positions. The Queen, for instance, is ordered to King three while in her starting position (can't be done). The "Knight to Knight's Bishop three" move is also impossible. When she is free to move to King three, though, the Queen goes there twice - without moving anywhere else in between.
Continuity mistake: When the Village doctors and technicians begin their procedure on the unconscious Number 6, one man folds the sheet and blanket back from his chest. A few shots later, the same man does this again.
Do Not Forsake Me Oh My Darling - S1-E13
Continuity mistake: Driving his Lotus through London, Number 6 passes a hearse. But when the shot cuts to a wider angle, the hearse disappears.
Continuity mistake: While the technicians are prepping the unconscious Number 6, there's no watch on the lamp table by the bed. One appears there, though, when the tech begins collecting the prisoner's personal items.
Continuity mistake: During the scene in the bell tower, watch the beach in the background. In one take, the tide is in. In the next, it is suddenly at low tide, with much more of the beach exposed.
Continuity mistake: Number 6 pushes the dead body out into the surf. In close-ups, the body is still very near the shore. But in long shots, it is much further out. (00:28:30)
The Girl Who Was Death - S1-E15
Continuity mistake: In the interior shot of Number 6 exiting the lighthouse, the red doors are open. When the shot cuts to an exterior view of him coming out, the doors are closed and he opens them again.
Continuity mistake: Number 6 recites a classified ad in Spanish to the young woman at the newstand. His phrase contains eight words, but when she reads them back, there are nine.
Continuity mistake: When Number 6 and Nadia get into the shipping crate, they're both able to stretch out completely for the 12-hour trip. But when the crate is opened, it's suddenly several inches shorter, and 6 has to bend his neck at an uncomfortably sharp angle to fit into it.
Continuity mistake: While he's making his graduation speech and demanding to know why Number 6 resigned, Number 2 has a mortarboard tassel wardrobe malfunction: it keeps changing sides between shots.
Visible crew/equipment: When Number 6 holds up the radio, the camera angle tilts just enough to show us a brief glimpse of the top edge of the studio set.
Free for All - S1-E4
Continuity mistake: During the campaign, watch the bass drummer as he turns left. The same taxi with the same driver passes him twice in quick succession - going in the same direction.
A. B. and C. - S1-E3
Continuity mistake: Number 6 substitutes clear water for the red-tinted drug in the syringe. But when Number 14 later injects him with the same syringe, the fluid in it has turned red again.
Continuity mistake: The judge has two glasses in front of him on the bar. When the shot changes, there's just one glass.
Continuity mistake: When Number 6 is setting up his antenna, there's a woman on the beach in the background in a blue bathing suit. Between takes, her beach umbrella disappears.
Continuity mistake: In the saloon, between close-ups and cutting back to the master shot, the glasses in front of the men at the bar change positions repeatedly.
The Girl Who Was Death - S1-E15
Other mistake: When the girl makes her getaway in the helicopter and Number 6 emerges from the bushes and climbs aboard, look at the trees on the horizon as the helicopter takes off and supposedly lands later in another location. You can see that the helicopter takes off and lands in the same field. Also, the shot of Number 6 hiding behind bushes before jumping on the helicopter, and after climbing off it is the same one. It's from a slightly different angle the second time, but it's the same bush.
Plot hole: When Nadia had been held captive in The Village, how did she get word to her accomplice to be ready at the exact time, in the exact location, and with a packing crate ready, and a whole series of transports arranged? Even if Nadia was in on the ruse of conning Number 6, wouldn't he be suspicious?
Continuity mistake: An estate car can be seen crossing the background in one scene, as opposed to the village "taxis."
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