Visible crew/equipment: Just after Missy treads on Osgood's glasses after killing her, you can see a boom mike shadow on the wall.
Visible crew/equipment: On the Moon's surface, the camera and boom mic can be seen reflected on the visor of the astronaut as she talks to Clara.
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