Continuity mistake: When Martha and Jenny are washing the floor, just as Hutchinson and Baines come along and tell them off for laughing, one of the lace ribbons on Martha's cap moves between hanging in the back in shots facing her and draped over her shoulder in shots facing the schoolboys. (00:04:15)
Continuity mistake: When Martha initially bursts into John Smith's study after hearing that he fell down the stairs, the door is mostly closed. When she runs back to the door to knock on it after Joan Redfern tells her off for bursting into a master's study unannounced, the door is open wider. (00:06:35)
Continuity mistake: During Joan's encounter with the Family's spaceship, when it shines a beam of green light at her, she shields herself by raising her right arm. It changes position between a wide shot and a close-up. (00:12:20)
Continuity mistake: After watching the Family's spaceship land, Jeremy Baines puts his hand on a tree stump as he walks around it to approach the ship. He does this twice, in two successive shots. (00:14:10)
Continuity mistake: When the Doctor fits the Chameleon Arch watch into the headset, his hands change position between shots. (00:20:15)
The Family of Blood (2) - S3-E9
Continuity mistake: As the scarecrow-soldiers advance on the school to do battle, the scene cuts to Sister of Mine, looking out from a school window. There is heavy rainfall outside. When we immediately cut back to the advancing scarecrows, it is a cold, clear night. (00:10:00)
The Family of Blood (2) - S3-E9
Continuity mistake: When Martha finishes listing off the bones of the hand to Joan, in order to prove that she's a medical student from the future, in a shot facing Joan, Martha's thumb is extended. In the next shot, facing Martha, her thumb is suddenly folded back, as if she was using her hand to display the number 4. (00:12:15)
The Family of Blood (2) - S3-E9
Continuity mistake: When Timothy opens the watch into the girl's eyes, Jeremy Baines shouts "Time Lord", then a few seconds later; "What are we waiting for. Attack!" There is then a shot looking down on the scarecrows, Jeremy and Jenny. If you look closely at Jeremy Baines, it's a different actor playing him. (00:16:20)
The Family of Blood (2) - S3-E9
Continuity mistake: When Sister of Mine enters the school's courtyard after the battle with the scarecrows, her right hand is holding her balloon at the bottom, with the bottom of the string wrapped around her left hand. In the next shot, facing her, her right hand is at her side, with the balloon floating above her left hand. The balloon proceeds to jump between positions until Sister of Mine murders the headmaster. (00:18:00)
The Family of Blood (2) - S3-E9
Continuity mistake: When the Doctor comes back to the Cartwright house after imprisoning the Family, Joan walks over to the window and looks out, clasping her hands in front of her. In the next shot, when she asks the Doctor if it's done, her hands are suddenly by her sides, and she is shown clasping them again. (00:34:45)
The Family of Blood (2) - S3-E9
Continuity mistake: When the Doctor and Martha hug after he thanks her for looking after him, the position of her arms changes between shots. (00:38:20)
Continuity mistake: When Sally pulls off the last piece of wallpaper to reveal the writing, "Love from the Doctor (1969)", in the first shot, the second "9" in the date is somewhat patchy, with the middle part of the number mostly gone due to the removal of the wallpaper. In a close-up of "The Doctor" just moments later, the "9" is intact, visible in the lower right corner. (00:02:15)
Continuity mistake: When Sally Sparrow is about to take the key from the weeping angel, at first the key is on a piece of string, and that string is wrapped around the weeping angel's left hand. In the next shot, and when she pulls the key out, the string is now only in the angel's palm. (00:10:30 - 00:11:10)
Continuity mistake: When Sally enters the DVD store looking for Larry, she encounters the store's owner, Banto, who is sitting behind the front counter watching a movie. He holds up his finger to indicate her to wait briefly because of the point in the movie he's at. In shots facing him, his hand is quite close to his mouth and chin, but in a shot facing Sally, his hand is considerably further away from his head. (00:13:10)
Continuity mistake: When Sally picks up the remote to pause the recording of the Doctor after getting unnerved by him seeming to hear her, and when she rests it against her forehead after Larry comes back into the room, it switches between her hands a few times. (00:16:40)
Continuity mistake: After Sally leaves the garage, Billy turns his head and sees the Weeping Angels around the TARDIS, and his facial expression changes from a smile to a confused frown. In a close-up of Billy after the shot of the Angels, his head is turning and his expression changes a second time. (00:20:40)
Continuity mistake: When Sally is holding the picture of Billy and his wife, the position of her right index finger on the frame changes between shots. (00:24:35)
Continuity mistake: When Sally takes out the list of DVDs while talking to Billy in the hospital, her grip on the paper changes between shots. (00:25:40)
Continuity mistake: When Lawrence is watching the Weeping Angel, just after seeing the Doctor's film/Easter egg, he turns away for a split second. By the time he turns back, you see the Weeping Angel's face only inches from Lawrence's face. But you then cut to a wide shot where you see the Angel's arms outstretched, so its face is about half a metre away from Lawrence's face. (00:34:45)
Continuity mistake: When Sally and Larry are hugging each other as the TARDIS dematerializes around them, as the cellar with the Angels becomes more visible, Sally lets go of the console with both hands and clasps them together. A couple of shots later, her left hand is still touching the console. (00:37:55)
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.