Audio problem: Before the TARDIS materialises in the haunted house, you can hear The Daleks' time machine sound effect for no apparent reason.
Visible crew/equipment: (Episode 5) When Vicki is in the jungle she happens upon the TARDIS and bangs on the door begging to be let in. In the next shot we can see the boom pole/mic hovering in the background, then a hand appears which seems to guide the actress to head in that direction. (00:07:45)
Visible crew/equipment: (Episode 4) After Ian shudders from the apparition he continues to follow The Doctor down the hall, and the camera casts a shadow on Ian. Then, when The Doctor finds the stairs leading to the laboratory he tells Ian he must see what's on the table. Just as Ian states his displeasure at the thought, the boom mic (and its shadow) pops up into view at the bottom of the screen, in front of Ian. (00:05:15)
Continuity mistake: When Frankenstein's Monster begins chasing The Daleks, he's wrapped in bandages. When he catches The Daleks in the room with the TARDIS, he's suddenly wearing a suit.
Revealing mistake: When the robotic Doctor first appears - and in many of the later scenes involving the jungle on Mechanus - it is very obviously not William Hartnell playing him, but a vaguely similar double. In addition, his lines have been dubbed by Hartnell and do not always match the movements of his mouth.
Continuity mistake: When the Doctor and Ian encounter the Frankenstein monster in episode four, you can see a Dalek behind them, even though it's long before The Daleks arrive in this time zone.
Factual error: In episode one, Abraham Lincoln seems to have affected a southern accent and put on some weight.
Continuity mistake: In episode four, when the Doctor and Ian return to Frankenstein's lab, the monster is lying on the table in the opposite direction from when they left.
Visible crew/equipment: Near the end of episode five as The Daleks plan their attack, a BBC camera can be seen in the background on the right. (00:21:20)
Revealing mistake: In episode 1 when the Doctor, Ian, Barbara, and Vicky leave the TARDIS, wheels are visible which move the prop around. There is also no back to the prop.
Visible crew/equipment: In episode four, when Ian and the Doctor descend the stairs into Frankenstein's lab, you can see a boom operator and mic behind Ian, at the left side of the screen.
Visible crew/equipment: (Episode 5) After The Daleks plan to organize a full-scale search of the jungle at daybreak, when it cuts to The Doctor and Ian, the shadow of the boom mic moves around at the left side of the screen. (00:16:35)
Visible crew/equipment: (Episode 6) At the very end, after Vicki and The Doctor have watched Barbara and Ian's return to 1965 on the Time-Space Visualiser, when Vicki hugs The Doctor the moving boom mic casts a shadow at the top, left of the screen. (00:24:30)
Revealing mistake: In episode 1 when the Doctor is checking the controls you can see the studio lights to the top left corner where the set doesn't completely connect.
Continuity mistake: Towards the end of episode 2 it's nighttime, but when Ian and the Doctor lure the Dalek over from the TARDIS, and when it falls, it's daylight.
Chosen answer: No, it was the result of the Cybermen's draining Earth of energy to their world, that also affected the Doctor, draining his energy as well, causing him to regenerate.
Also In the episode it's said that his body was wearing thin.
Dan23