Revealing mistake: Watch the scene where Uvanov sticks a Laserson probe into the head of one of the Vocs (V4) as it is strangling the Doctor. After he shoves the probe in, you can quite see the suit's helmet come away from the rest of the suit.
Revealing mistake: Watch really closely when Leela throws the knife at one of the robots. You can see the knife fall to the floor about a second after she throws it. Then, of course, the next shot shows the knife sticking out of the robot's chest. Guess Leela isn't quite as good a shot as we thought.
Visible crew/equipment: When Leela runs into Toos' quarters (and finds D84 leaning over Toos), we see a low-angle shot of her entering the room. Look at the brief shots of her before and after D84's line, "Please do not throw hands at me," and you'll see the front of the camera that took that low-angle shot jutting out into the doorway behind her, before it slowly retreats out of vision.
Continuity mistake: The Doctor's scarf vanishes while he's detained in the crew's quarters.
Revealing mistake: When the Doctor and Leela are put in Uvanov's cabin to await questioning there is a shot of a robot listening to them in which you can see the actor's neck.
Revealing mistake: When SV7 comes into Taren Capel's workshop, its usual eyes are missing - only black discs are visible (later in the scene, these are overlaid with the red speckled pattern to show the robot being reprogrammed).
Other mistake: In episode two, when Poul enters the room where Uvanov and D84 are holding Leela, the body of Cass breathes.
Revealing mistake: When Taren Capel is modifying a Voc robot, there is a shot of the robot's agitated hands as he reassures it. On the robot's silver gloves, the "Marigold" logo is visible. ('Marigold' make rubber gloves that are used when washing dishes). Perhaps that particular Voc robot had been assigned to dish-washing duty that day...
Continuity mistake: From time to time in episode four, the "frozen" robots on the command deck can be seen to wobble - the most noticeable is when SV7 is threatening Uvanov over the communicator.
Visible crew/equipment: In episode three, when Toos talks about the disposal of robots, a crewman can be seen behind her, toward the back of the set.
Revealing mistake: When the Doctor confronts D84, the robot is shown in profile as the Doctor forces it to speak. The movement of the actor's jaw is visible behind the mask.
Revealing mistake: Immediately after the Doctor stabs SV7 in the back of the head and the robot crashes to the floor, the next scene shows the fallen figure of SV7 in the background - breathing heavily, with his chest moving up and down.
Revealing mistake: Near the end of episode one, the Doctor peers into a hopper and sees ore piling up inside. The image of the ore wobbles back and forth.
Revealing mistake: At the beginning of episode four, when the Doctor is surrounded by robots, we initially see SV7 with *blue* eyes. Clearly someone forgot to add the glowing red-eye CSO.
Revealing mistake: In Episode 3, when Dask is cutting the wires, the second explosion happens too early.
Continuity mistake: In episode four, when the Doctor is patching the communicator into the android's head, he takes off the communicator's top, yet it is back on a few seconds later.
Visible crew/equipment: When Leela bandages Toos' arm, a member of the crew is visible on the edge of the set.
Continuity mistake: When Toos is being hunted by a robot, she shuts the door on its hand. When you see this scene from the inside of the room, the robot's hand is trapped at a different place to the next shot, which is from outside the room.
Continuity mistake: When Uvanov captures Leela he says she has killed three people, but he only knows Chub and Cass are dead. Then Poul tells him about Kerril.
Revealing mistake: When the Doctor is trying to unlock Uvanov's cabin door, Leela goes to join him and grabs the edge of the metal railing, which bends badly and then goes back to its original shape.
Answer: TARDISes are generally available for properly authorised use on Gallifrey; they're not usually assigned to a particular Timelord on a long-term basis. The Doctor stole his when he left his homeworld.
Tailkinker ★