Revealing: Susan is supposed to be running through a forest. It is painfully obvious that, in fact, she is simply running on the spot against a back-projected film, and the branches that hit her are simply studio stagehands, hiding just out of shot, hitting the actress with twigs.

Visible crew/equipment: The boom mic makes an quick appearance about 18 minutes into episode one. It is in the upper left corner when the camera switches from a close up of the Doctor and Susan to a medium shot of all four characters.

Factual error: The tribe that Doctor Who meets is definitely Caucasian in appearance, which rules out Asia and the Americas as possible locations. Modern humans didn't reach Europe until around 30,000 years ago, so the date implied by the title is wrong. Also, the tribe is definitely NOT Neanderthal, as they apparently didn't have a tribal system.

Revealing: During the long continuous hand held shot of Ian and Barbara exploring the junk yard in episode one, the cameraman trips, making the image jump up and down.

Plot hole: When Ian is trying to escape from the Tardis in episode 1, he says, "He closed the door from over there, I saw him." Although it is in fact Susan who closed the door.

Continuity: When Ian and Barbara enter the TARDIS for the first time, Susan operates the door switch. Later on, when the Doctor electrocutes Ian, he uses the exact same switch.