The Sea Devils: Episode Two - S9-E10
Continuity mistake: In episodes 2 and 3, watch the clock on the wall in the Master's quarters. When the Master pulls a gun on the Doctor and the Doctor quickly pulls the door shut, the clock shows ten minutes to three. In the next episode, after the swordfight is over and the Doctor is being led out by the guards, the clock now shows approximately eight minutes after twelve.
The Sea Devils: Episode Three - S9-E11
Continuity mistake: The helicopter sent to rescue the Doctor and Jo changes in mid flight. It begins as a grey Sea King marked SO. In the second shot, it has an orange nose and tail stripe and is numbered 56.
The Sea Devils: Episode Six - S9-E14
Continuity mistake: The Doctor and the Master partake in a boat chase. They are both soaking wet when they arrive at land but in the next shot their hair and clothes have magically dried.
Continuity mistake: (End of Ep. 3 and start of Ep. 4) When The Third Doctor fights the dark side of Omega's mind, the rings that The Doctor wears on the pinky fingers of both hands switch to his ring fingers, then back again to his pinky fingers, between shots. Then as Omega chokes The Doctor, the ring on his right pinky vanishes between shots.
Continuity mistake: At the end of episode one, when the Doctor and Taron spray paint onto the invisible Dalek, they use two different colors. At the start of episode two, the Dalek is suddenly black and painted on all sides.
Continuity mistake: When Wester - an invisible Spiridon - is treating Jo's arm, his shadow can be seen.
Continuity mistake: In episode five, Jo's hairstyle changes. She has one hairstyle in the bulk of the episode, which was filmed in the studio. And a different one during the "Plain of Stones" scenes, which were shot on location.
Continuity mistake: In the very first scene of the story, Jo is holding a gun as she opens the TARDIS doors, but when they come into the console room, she has no gun and is using both hands to support the Doctor.
Continuity mistake: In episode five, the Doctor escapes from Global during the day. When Yates is caught it's dark, but the next scene, on the slag heap, is in daylight again.
Invasion of the Dinosaurs - S11-E2
Continuity mistake: In episode 2, when the Doctor and Brig arrive at the scene to stun the dinosaur, they leave the stun gun in the jeep. Mike Yates glances down at it and we can see that the sabotage disk is already attached - although he doesn't actually put it on until later.
Invasion of the Dinosaurs - S11-E2
Continuity mistake: In episode 3, Sarah is hit on the head by debris knocked loose by the escaping dinosaur. It hits her on the back of her head or shoulders - but the later bruises and scratches are on her forehead.
The Monster of Peladon - S11-E4
Continuity mistake: In episode three, Eckersley turns on the security monitor. The very first image is of the entrance to the refinery, but it does not show the Doctor and Gebek trying to break in. Eckersley then flips through the images and finds one of the refinery with the Doctor and Gebek breaking in.
The Monster of Peladon - S11-E4
Continuity mistake: When opening the door to the refinery, the Doctor leaves his sonic screwdriver on top of the panel. However, a few seconds later, when we next see the panel, the sonic screwdriver has disappeared.
The Monster of Peladon - S11-E4
Continuity mistake: In episode six, the Doctor is using the Aggedor statue to fight The Ice Warriors. The door to the refinery was partially destroyed by The Ice Warriors earlier. But in every shot of Aggedor appearing or re-appearing, the door can be seen intact at the edge of the shot.
The Monster of Peladon - S11-E4
Continuity mistake: In episode six, the same extra is killed by both Azaxyr in the ambush and by Eckersley later on.
Planet of the Spiders - S11-E5
Continuity mistake: In episode two, Lupton steals a boat, throwing the pilot into the water. Moments later, we see him struggling with the pilot again - who is perfectly dry.
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.
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.
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)
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 ★