Continuity mistake: For most of the scene where the Doctor and Donna find the dying Ood Delta-50, the front of his body is covered in snow. After he mentions "the circle", when the Doctor is asking what that is, the snow on Delta-50's chest is gone. In addition, the Doctor's hands change position between shots. (00:06:25)
Continuity mistake: During the first scene in Warehouse 15, when Dr. Ryder puts his hands on the railing as he looks over it, the exact positioning of his right hand changes between shots. (00:15:05)
Continuity mistake: When the Sybilline priestesses kneel after the High Priestess speaks, in a shot from the front, Donna, sitting on the altar, has her hands in front of her - she's using her left hand to take the rope off her right wrist. In the next shot, from behind, her hands are at her sides. In addition, the rope still on her right wrist disappears. (00:27:05)
Revealing mistake: When the Doctor and Donna are walking through the underground tunnels towards Mount Vesuvius, tunnels that can be presumed to be fairly warm due to their connections to volcanic activity, their breath is visible - something that only happens in cold temperatures. (00:31:20)
Continuity mistake: When the Doctor explains to Donna how he sees the universe, the distance between them changes several times. (00:31:40)
Continuity mistake: When the Doctor is talking to Evelina at the end, her hair changes position between shots. (00:44:00)
Continuity mistake: When the Doctor and Donna leave as Caecilius, Metella, Evelina and Quintus stand and watch the destruction of Pompeii, the TARDIS changes orientation between shots - in both of them, one from in front of the family and one from behind, the TARDIS' door, with the sign, is visible. (00:45:10)
Continuity mistake: After Metella hands Caecilius the beetle brooch, his hands change position between the close-up and the wide shot. (00:46:10)
Continuity mistake: When the Doctor and Donna are talking to Caecilius, when they introduce themselves as "Spartacus" and Caecilius makes several guesses as to their relationship, wondering if they're married or siblings, in shots facing them, the Doctor and Donna are standing fairly close together. In shots facing Caecilius, however, the Doctor and Donna are standing much further apart. (00:11:05)
Continuity mistake: After Lucius' arrival, when the Doctor escorts Donna towards the TARDIS, telling her they have to go, which she doesn't agree with, between shots his hands change position between having his right hand on her back, or having both his hands on her shoulders. (00:13:55)
Continuity mistake: When the Doctor and Caecilius are talking while the Doctor examines the hypocaust, Caecilius keeps changing position. (00:17:40)
Continuity mistake: In Lucius' house, when the Doctor pulls the cloth off the shelf with the stone circuits, the position of Quintus' hand on the shaft of the torch he's holding changes between shots. (00:19:10)
Continuity mistake: When Donna changes into contemporary clothing, she has a purple shawl of sorts draped over her dress. In the first shot, she's shown with her hand out from under the cloth, but in the next shot her hand is under the cloth. (00:19:30)
Continuity mistake: When Ms. Foster's computer switches back on because it's picking up a signal from the Adiposian First Family, in a shot facing him, the Doctor reaches towards it with his left hand. In the next shot, from behind him and Donna, his left hand is resting on the wall next to the computer, before he reaches for it again. (00:39:25)
Continuity mistake: When the Doctor attempts to persuade Matron Cofelia, who is hanging in a levitation beam, to come over to the roof of the Adipose Industries building, Donna's hands, resting on the parapet on the edge of the roof, change position between shots. (00:41:15)
Continuity mistake: When the office worker gives the Doctor her phone number, he's holding the paper differently between the wide shot and the close-up. (00:04:35)
Continuity mistake: When Donna starts fiddling with the Adipose necklace she stole, this causes an Adipose to be created out of Stacey's fat cells. When this begins, Stacey is in the upstairs bathroom applying lip gloss, and she's holding the applicator wand when her stomach begins to move. When she pulls up her shirt to look at her distending stomach in the mirror, the lip gloss wand is gone. (00:07:15)
Suggested correction: Actually, it looks like she finished putting on lip gloss and put the lid with the applicator back on just before she starts feeling queasy from the impending Adipose birth.
Continuity mistake: When the Doctor is leaving Roger's house, a gadget in his pocket starts beeping. He pulls the device out with his left hand, but in a close-up of it immediately afterwards, it's in his right hand. (00:07:35)
Other mistake: When the Doctor and Donna get onto the roof, after he sonics the door shut behind them, as they run for the crane for the window washing cart he puts his sonic screwdriver in his mouth, holding it between his teeth, and pulls something out of his pocket. It looks like he might be carrying Miss Foster's sonic pen - except that at this point in the episode, it hasn't yet been revealed. (00:24:20)
Continuity mistake: When Donna attempts to smash open a window with a wrench she finds in the window washing cart, there's a shot of her and the Doctor from above where they're not in front of the window they were at in shots from inside. (00:26:00)