Free for All - S1-E4
Continuity mistake: Number 6's bed tidies itself in the scene where the spying lamp is lowered from the ceiling. First the bedcovers are rumpled and disarrayed. Then in the next shot, all is straight with the blanket neatly folded at the foot.
Continuity mistake: While the gunrunner is untying the raft, he's holding a half-eaten green apple in one hand that wasn't there in the previous shot. It disappears again as the raft floats away. Then it comes back - but it has now become a red apple instead of a green one.
The General - S1-E6
Continuity mistake: At the Village cafe, the menu on the table turns itself 90 degrees between the master shot and the close-up. Number 6's hand position and one of the chairs also both change positions instantly.
The General - S1-E6
Continuity mistake: In The General's office, the professor pulls the sheet of paper he's been typing on out of the typewriter and inserts it head-first into the computer. When we cut to a close-up of the paper going in, however, it is now being inserted bottom-first.
Continuity mistake: Between shots, the bodies of both Kathy and the Kid change positions on the floor. Kathy's has moved away from the stairs, and the Kid's reverses directions.
Continuity mistake: In full shots, the judge's cigar is in his mouth. Every time a close-up is intercut, the cigar is in his hand.
Continuity mistake: Number 6 points the mirror out to sea and tries to send a signal. But when we see him from the POV of the security camera, he's pointing the signal mirror toward the Village instead. When the shot cuts back to him on the beach, the buildings are again behind him and he's facing seaward again.
Continuity mistake: In the final scenes, as helicopters are taking off from the Village, the bell tower that's always been there is visible in some shots, but in others, it has disappeared.
The Girl Who Was Death - S1-E15
Continuity mistake: When the bulldozer is on fire, the raging flames have died down completely in one shot, but are instantly burning brightly again in the next one.
Continuity mistake: Twice in this episode (once in the saloon and once in the sheriff's office), Number 6's coat is unbuttoned when he's inside, but has instantly buttoned itself up when he runs outside.
Do Not Forsake Me Oh My Darling - S1-E13
Continuity mistake: In Number 2's office, the Colonel stands at the bottom of the ramp. In the next shot, however, he's suddenly beside the tea cart instead.
Continuity mistake: Nadia's number badge is upside down when she serves Number 6 breakfast. It's turned itself right-side up when she leaves, though.
Continuity mistake: In long shots of the truck transporting Number 6 and Nadia, the crate they're supposed to be hidden in disappears from the truck bed.
Continuity mistake: When the lamp begins spying on him, Number 6's bed sheets and blanket rearrange themselves from messy to neatly tucked in between shots.
Continuity mistake: When Number 6 falls on the beach, the sand under him is wet. In the next shot, it is obviously dry.
Continuity mistake: The towel in Number 6's locker changes colors. When we first see the locker opened, the towel is white. A few shots later, when it's opened again, the folded towel has turned blue.
Continuity mistake: Rover herds the boat back to the beach, and several people who were aboard minutes before (some of them unconscious) have somehow disappeared from its decks.
Continuity mistake: Alison is thanking Number 6 for letting her practice on him. In close-ups, her hands are at her sides. But in longer shots, she has her hands folded under her chin.
Continuity mistake: In the court room scene, Number 6 has wind-blown hair in the master shot, but is nicely combed up and neat in all the close-ups.
The General - S1-E6
Continuity mistake: Number 6 holds the Penny Farthing pass in both hands in close-ups, but in all the master shots, he has it in just one hand.
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.