Continuity mistake: When Cassandra reveals her presence to the Doctor, she starts off by turning him to face her, then pulling his tie out of his jacket with her right hand and tightening the knot with her left hand, in a shot facing him. In the next shot, facing her, she has her right hand holding the knot of the tie. Finally, just before Cassandra reveals her identity to the Doctor, shortly later, which hand is holding the tie changes again.
Continuity mistake: When Cassandra, possessing Rose, confronts the Doctor after he wakes up in one of the clone pods and tells him how she intends to kill him, her hand changes position between the shot from inside the pod, when she rests her hand on the front, and the next shot from outside the pod.
Continuity mistake: When the TARDIS crash-lands at the beginning, it comes to a halt in a corner of the Powell Estate's courtyard, by the garbage containers. Later, when Rose is watching through the window as blood-controlled people walk through the courtyard, the TARDIS has moved further out into the plaza.
Continuity mistake: At the beginning of Rose and Jackie's conversation in the kitchen about the Doctor, Rose takes a piece of food out of the fridge. Moments later, when she rests her hand on the light switch by the door, it has vanished. At no point in the intervening time did she come anywhere near a spot where she could have put it down, and she didn't eat it either.
Continuity mistake: When Daniel Llewellyn meets Harriet Jones, she pulls out her ID card when she introduces herself. The scene cuts to a shot of Llewellyn saying that he knows who she is, and when it cuts back to Harriet, the ID card has vanished without her making any movement to put it away.
Continuity mistake: At the beginning of the scene where Rose, Jackie and Mickey are in the restaurant, in the wide shot, Rose moves her left hand to the side of her head, while looking down with her head facing towards the other side of the table, which her elbow is resting on. In a close-up immediately afterwards, she's looking out the window with her hand to her face and her elbow resting on the windowsill.
Other mistake: After Jack uses Davitch's information to complete the Controller's coordinates, the Doctor uses a remote to project a holographic, transparent screen of the location in question. The image shows Orion's Horsehead and Flame Nebulae. In a shot immediately afterwards, looking through the holo-screen back at the Doctor and company as he explains what's going on, the image of the nebulae is not mirror-reversed as it should be, but is the same orientation as in the previous shot. The kicker is that the image of the nebulae has been altered, as well: it's already been mirror-reversed - in the actual sky, the Flame is left of the Horsehead.
Continuity mistake: When the Doctor is looking at Rose's hands, turning them over repeatedly, while she's describing how she was hanging from a barrage balloon, there's one moment where her hands are turned palm-up in a shot facing her, but back-up in a shot facing him.
Continuity mistake: During the Doctor and Nancy's conversation at her hideout, in shots facing her there is a bright circle of light cast on the wall to her left, which her shadow partially overlaps. In shots facing the Doctor where both him and Nancy are visible, the circle is gone, and Nancy's hideout is noticeably more dimly lit.
Continuity mistake: When Rose and Adam are in his workshop talking about aliens, during the exchange where she asks him about people who claim they've been in spaceships and he responds that he thinks they're nutters, Rose is poking around with her right hand at a storage shelf on the wall before moving her hand to a pile of boxes stacked on a table. When the scene cuts to a close-up of her, her hand has jumped back to the shelf.