Revealing mistake: No automobiles are permitted in the Village - ever. Yet in aerial shots, a black car is sitting behind Number 2's residence.
Continuity mistake: Watch the stone boat in the background as Number 6 and Number 2 discuss the oldsters having "every comfort." Between shots, the senior citizens vanish from the boat.
Continuity mistake: Rover drags Number 5 back out of the water to the beach and drops him with his feet pointing toward the recovery vehicle. He starts to get up, but when the shot cuts, he's lying flat again and has changed orientation on the sand, his head now pointing toward the vehicle.
Continuity mistake: While the prisoner is packing for his trip (in the opening title sequence), a beach photo placed in his travel bag rotates itself into a different position between shots.
Continuity mistake: The dwarf Butler climbs in to pilot the helicopter - but when the aircraft actually takes off, it's obvious that the pilot is a full-sized person.
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.
Continuity mistake: Due to a very poor edit, an extra walking past Number 2 and Number 6 as they talk on the patio disappears in mid-shot.
Continuity mistake: When Number 6 first wakes up in his new house in the Village, there's an ornately carved wood panel covering the window. When he stands, it has disappeared.
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.
Visible crew/equipment: As Number 6 storms out of Number 2's chamber, the camera dolly is briefly visible moving out of his way at the lower left of the screen.
Continuity mistake: When Number 2 is shouting at Number 14, calling him a traitor, Number 2's long strands of hair are flying all over his head. In the very next shot, though, his hair has nicely combed itself and he's well-groomed again.
Deliberate mistake: The credits list "Number 86" as played by John Maxim. But no such character appears in the episode. Apparently, 86 was left on the cutting room floor, but the titles weren't altered accordingly.
Free for All - S1-E4
Continuity mistake: Number 2's long neck-scarf changes when he steps into Number 6's house. It gets longer on the right side after he comes in the door.
Continuity mistake: Number 39 is writing notes on the word association test in her notebook. When the shot cuts to a close-up, however, the notebook disappears from her hands. It's back a short time later.
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.
Free for All - S1-E4
Continuity mistake: Number 6 grabs the boat hook and pulls the mechanic into the water. With a sudden shift in camera angles, the hook instantly vanishes from the falling man's hands.
Continuity mistake: The telephone kiosk Number 6 uses at the beginning changes both its shape and its location between takes. Sometimes it's under an archway: in other shots, it's next to the restaurant instead. And in some shots, the hood above the phone has square/straight edges, while in others, its edges are round.
Other mistake: They search for the location of the Village by using map co-ordinates, which are checked out using a military aircraft. The Village is eventually discovered and found to be on an island somewhere in the Mediterranean sea. Number 6 is ejected from the aircraft back to the Village. However, in the final episode, i.e. 'Fall Out,' the Village is found to be in somewhere in the UK. They escape in a truck and end up traveling to London.
Factual error: Number 6 wakes up to find the Village deserted, but the central plaza fountain is still running - until he looks at it from the bell tower, when it's suddenly off. The Village fountains never appeared to be on timers (they were always on, day and night), and no one is there to turn the water off, yet it's somehow still off when Number 6 returns at the end.
Free for All - S1-E4
Continuity mistake: While Number 6 and the maid are in the kitchen, the toast rack moves itself several feet in between takes. It's on Number 6's right, then suddenly appears on his left instead.
Answer: It's even more obvious than you think, you know who number 1 is in the very first episode. When 2 replies to the question "who is #1?" Change the way he answers from you are number one (in the monotone or accented answer to, "You are, number 6. The comma gives you the answer. #6 is #1. It's the tone of the answer.