Continuity mistake: Just after they break out of the prison cell, you see Lynda reach for her gadgets twice. (00:32:20)
Continuity mistake: Rose Tyler's hairstyle changes from shot to shot when she is discussing being 'the last human' with Cassandra. Rose's hair is in one style for the long shots, and another style for the close-ups.
Continuity mistake: When the Doctor takes to the nightclub stage to ask if anything has fallen from the sky, he has his right hand and arm up and gesticulating. But in several other shots of him from behind, it is his left arm that is up and moving. (00:04:20)
Continuity mistake: As the room that Rose is in gets scorched by the blazing sun, the level of burning is above her head in close up shots, but at Rose's head height in wide shots. (00:29:40 - 00:30:01)
Continuity mistake: When the three bride Autons attack Jackie, and they open their hands one at a time, it is clear that when the second Auton opens its hand, all three are already open. After it cuts to Rose, and back to Jackie again, the third one opens (even though we just saw it already open). (00:38:15)
Continuity mistake: When Suki discovers the bodies on Floor 500, she drops her flashlight, but in the next shot she's holding it again. (00:15:20)
Continuity mistake: When the Doctor and the housemates in the Big Brother house are watching TV, the brand name of the TV - Sony - appears in some wide shots, but is absent in other wide shots and all close-ups. (00:14:10)
The Parting of the Ways (2) - S1-E13
Continuity mistake: Near the beginning of the episode, the Doctor and Jack destroy a Dalek who is inside the TARDIS. It is seen again later when the Doctor, Rose and Jack come back into the TARDIS after talking with the Dalek Emperor. Yet later when the Doctor is sending Rose home, there is no destroyed Dalek. (00:14:20)
Continuity mistake: As the Doctor, Captain Jack and Lynda with a Y have been captured, the Doctor turns his head to the right, then after it cuts it shows him turning his head again and saying "Let's do it." (00:32:05)
Continuity mistake: When the Doctor pulls the arm off the Auton and tosses it to Rose, the arm is bent at the elbow and solid plastic, with a smooth, clean break. Later, particularly noticeable when Rose has left the department store, the arm is hollow, with an unbent elbow and a jagged break. The arm continues to change between the two appearances for the rest of its screentime. (00:07:08)
Continuity mistake: During the opening montage, showing the Slitheen incapacitated by electrocution, when Margaret drops Indra's body and stumbles back, a close-up of the body on the floor shows her legs without the pulsing electricity covering her entire body, which is visible in other shots.
Continuity mistake: When Harriet Jones is hiding in the closet and spying on the Slitheen attacking General Asquith, wide shots of the closet door have it in shadow, but close-ups of Harriet have the part of her face that is visible illuminated.
Continuity mistake: When Indra Ganesh offers Joseph Green the briefcase with the Emergency Protocols, he's holding it with the handle in his right hand in wide shots, but with it in his left hand in close-ups of him. (00:12:36)
The Parting of the Ways (2) - S1-E13
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. (00:18:50)
The Doctor Dances (2) - S1-E10
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. (00:18:25)
Continuity mistake: When the Doctor meets Nancy, when she warns him not to answer the TARDIS' ringing (fake) door phone, in a shot facing her he's holding his jacket away from his chest, but in the next shot facing him that hand is empty. (00:06:55)
Continuity mistake: When Jack is scanning Rose onboard his spaceship during their conversation, he leans against a metal railing in front of The Pilot's seat twice, in two successive shots. (00:20:40)
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. (00:23:15)
Father's Day - S1-E8
Continuity mistake: When Rose checks her messages while riding in Pete's car and hears the very first phone call instead, the positions of her fingers change between the wider shot and the close-up. (00:13:30)
Chosen answer: 1) When Stephen Moffat took over he ignored a lot of what had been developed before (there is not in-universe answer). 2) It would have killed Rose, so the Doctor absorbed the energy. His body regenerated before the energy could do a significant amount of damage that would prevent regeneration.