Revealing mistake: Perhaps criticizing the special effects is unfair, but the extremely obvious use of toy tanks and a rag-doll Sarah in certain scenes is one of the worst examples in the history of the show.
Continuity mistake: At one point in the story, the Doctor hurriedly types out a letter to leave for the Brigadier and Sarah Jane, and pins it to the TARDIS. Later when Sarah Jane reads the note, you can see it's been handwritten.
Plot hole: The linchpin of the plot makes no sense whatsoever. In an effort to diffuse international tension, the superpowers would allow Britain to publish the codes that would allow anyone in the world to launch their nuclear missiles? And then, after going through the drama of not one but two countdowns, it's revealed that the superpowers can just activate safety over-rides to prevent the launch. So how in Hades did the SRS have any threat whatsoever to wield over them and issue their demands?
Audio problem: When the Doctor chops a brick in half, you can tell that the brick is really made from balsa wood by listening to the sound it makes when it hits the ground.
Other mistake: When the K1 Robot breaks out of Kettlewells factory in part 2 or 3, it trips up.
Deliberate mistake: Benton is a Warrant Officer in this story, but the end credits refer to him as "Sergeant Benton".
Revealing mistake: In the last part, the giant robot steps on a soldier. There are several things wrong with this scene. 1) You can see the matte halo around the robot's foot. 2) The robot does not leave a footprint. And 3), after the soldier gets squashed, his arm is visible waving over the robot's foot.
Revealing mistake: When Noah bangs his green arm down, in a close-up you can tell that the arm has green bubble wrap around it. (00:02:30)
Continuity mistake: When the Doctor and Harry arrive in the cryogenic chamber, they walk around for some time inspecting the chamber and talking. Towards the end, they notice a green slime trail newly appeared on the floor. But the trail was visible in the very first overhead shot of the chamber.
Revealing mistake: When Vira emerges from the hibernation chamber, the Styrofoam that forms the pallet squeaks.
Revealing mistake: As the cast move through the transom of the space station, observe the starscape through the lower windows. At certain points you can see a thin strip of light where the black curtain used for the stellar backdrop meets the studio floor.
Deliberate mistake: In episode three, the Doctor and Vira meet a half-changed Noah. He holds a gun on them, then drops it at Vira's feet and the door is suddenly closed. This is because the scene was originally longer and involved Noah begging Vira to kill him before the Doctor shuts the door. It was trimmed down to get it past BBC censors.
The Sontaran Experiment - S12-E3
Continuity mistake: In Episode 2, when the Doctor calls Harry from the Control Room and Harry enters the room next to the Cryogenic Chamber, there is an oblong yellow panel next to the door. It extends from about Harry's waist line to about 200mm below the top of the door. But in Episode 3, when Noah calls Vira from the control room part way into his transformation, and everyone runs into the adjacent room, the panel is mounted differently. It now extends from about Harry's mid-torso, to the top of the door frame. (00:03:35 - 00:09:32)
Genesis of the Daleks - S12-E4
Continuity mistake: When Sarah falls from the scaffolding, a plank of wood saves her from death. Trouble is, she fell a foot from the outside of the scaffolding and most of the plank was inside the scaffolding, therefore her feet would have hit it and she could only have landed with her head pointing inwards. But when we see her, her head is pointing outwards. (00:01:25)
Genesis of the Daleks - S12-E4
Revealing mistake: During the Doctor's early conversation with the Time Lord, there is fog swirling around them. When the Doctor agrees to take on the mission, it suddenly appears very concentrated around the tip of the rocks behind them, as if generated from a source behind the rocks. Normal fog would not do this, and it's clear that dry ice was used as the fog effect (DVD commentary confirms this). (00:02:45)
Genesis of the Daleks - S12-E4
Visible crew/equipment: Just after The Daleks move past the Doctor and the female Thal soldier in the corridor, a piece of lighting equipment is reflected on the wall behind her. (00:08:00)
Genesis of the Daleks - S12-E4
Continuity mistake: When the Doctor drops the time ring, it lands very close to the wall. When he picks it up later, however, it's in the middle of the corridor. (00:09:40)
Genesis of the Daleks - S12-E4
Revealing mistake: When Ronson is killed by The Daleks, you can see Ronson reacting a little too soon to the Dalek laser. (00:14:40)
Genesis of the Daleks - S12-E4
Visible crew/equipment: In episode 1, when General Ravon is being held at gunpoint and he says 'they won't last much longer', the shadow of the boom pole is moving on the door behind him. (00:15:15)
Answer: In 'The Five Doctors', three separate Cyberleaders are definitely used. So it's likely that Cyberleaders are like unit commanders, of which a fair-sized army might have several.
Daria Sigma