The Sontaran Stratagem (1) - S4-E4
Continuity mistake: When the clone Martha sits up in the tank, in a shot from behind her the umbilical cord is trailing down her back. In a shot facing her, it's draped over her shoulder, only to return to being down her back when she unplugs it. (00:35:20)
The Sontaran Stratagem (1) - S4-E4
Continuity mistake: When Jo Nakashima says, "If you won't listen, I'll find someone else who will," she's holding her purse and bundle of papers in the crook of her left arm. When she opens the door of her car, the items have jumped to her right arm. (00:00:45)
The Sontaran Stratagem (1) - S4-E4
Continuity mistake: When Private Harris orders the two hypnotized workers in the basement of the ATMOS factory to let him through the door they're guarding, he's holding a torch in his left hand, and when shown from behind has that hand down by his side. In the Sontarans' video feed, which also shows him from behind, his left hand is on his assault rifle. (00:11:15)
The Sontaran Stratagem (1) - S4-E4
Continuity mistake: When General Staal surprises Privates Harris and Grey in the room with the cloning tank beneath the ATMOS factory, the position of his right hand, holding his command baton, changes between shots several times. (00:14:10)
The Sontaran Stratagem (1) - S4-E4
Continuity mistake: When Martha asks the Doctor to look at her so she can point out she's not carrying a gun, he's sonicing an ATMOS device, and he lowers his hand when she speaks. In the next shot facing Martha, the Doctor's hand is raised again. (00:16:10)
The Sontaran Stratagem (1) - S4-E4
Continuity mistake: When the Doctor gets embarrassed as Donna lightly mocks him for not realizing that when she said she wanted to go home, she only meant for a brief visit, he rubs his chin with his left hand. When Ross Jenkins interrupts by saying, "Ready when you are, sir," the Doctor is now rubbing his chin with his right hand. In the shot after that, it's back to his left hand. (00:20:40)
The Sontaran Stratagem (1) - S4-E4
Continuity mistake: When Ross makes his "round the bend" pun while turning the Jeep onto Rattigan Academy's drive, the road seen doesn't match up with what's shown on the GPS display. (00:26:20)
The Sontaran Stratagem (1) - S4-E4
Visible crew/equipment: As the Doctor tries to get Wilfred out of the car, the camera goes to follow his movement and there is a reflection of the lighting rig and camera on the car.
The Sontaran Stratagem (1) - S4-E4
Revealing mistake: In the beginning, the ATMOS system takes the car to the Thames, then runs it into the river. At first, the car runs forward normally. After the angle change, there's a huge white cloud of mist behind the car that dissipates quickly, meaning an air cannon of a sort was used to propel the car into the river. (00:02:35)
The Sontaran Stratagem (1) - S4-E4
Continuity mistake: In the TARDIS as Donna navigates, the Doctor uses a hammer to help correct the trajectory, then rests it on his neck and shoulder. A second later, when the phone rings, his hand, holding the hammer, is suddenly much lower, below his waist level. (00:03:15)
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.