The Impossible Astronaut - S6-E2
Audio problem: When the Doctor sits in the Oval Office chair, Secret Service Agents aim their revolvers at him. As they do, the sound of a pistol slide racking is heard. None of them are doing anything except raising and aiming their revolvers at him.
Audio problem: When Idris/TARDIS says to the Doctor "And you don't care that it's impossible", in a shot from behind them her jaw does not move as she speaks. (00:22:49)
A Good Man Goes to War - S6-E8
Audio problem: When Madame Kovarian says, "Give the order, Colonel Runaway," she is seen facing three-quarters away from the camera. Her jaw does not move as she speaks. (00:25:10)
The Wedding of River Song - S6-E14
Audio problem: When Amy says the last two words of "Do you know what else he is, Madame Kovarian?", her mouth doesn't move. (00:34:07)
Chosen answer: The Master knows that deep down, he deserves death for the crimes that he's committed throughout his life, and since he regards The Doctor as his arch-foe, he expects it to be at his hands. The fact that The Doctor is still willing to forgive him for all of his crimes hurts him more deeply than death would.
Captain Defenestrator