By replacing the claw with a plunger, the Doctor is inadvertently responsible for the deaths of Simmons in "Dalek" and Dr. Singh in "Doomsday", who were both plungered to death. Of course, had the claw remained intact, their fates may have been arguably more brutal.
The Doctor gave the Daleks their catchphrase when he unwittingly said "exterminated". "The Witch's Familiar" revealed that when a being pilots a Dalek casing, "exterminate" is also the command to fire their gunsticks. The Doctor is even more steeped in blood from innumerable victims of extermination.
That said, it's lessened by the fact that they would have any command to fire their energy weapons, and they just so happened to adopt the one that the Doctor mentioned, which is essentially cosmetic in nature. And compared to kill, takes longer to say.
