MURDER BY DEATH
Moffat: Sherlock works out that the only way to stop Magnussen is to shoot him in the face, so he does. Most people can’t do that. Most people wouldn’t just go bang.
Gatiss: You don’t want to get bogged down in some dreary procedural about it all. It’s got a sort of operatic quality to it, which is what makes that ending, I think, very powerful.
Moffat: Also, if you read [The Adventure Of] Charles Augustus Milverton, Dr. Watson in the opening paragraph tells you that he’s about to tell you a porkie. He says, ‘I even now must be very reticent.’ I think what Doyle is hinting at is that Sherlock Holmes and Dr. Watson sat in Baker Street and said, ‘Right, we’re going to have to go and kill him, aren’t we? That’s the only way we can do this.’ So they break in, kill him, and then Dr. Watson writes up a version of the story that puts the murder [on someone else].
Gatiss: They’re hiding in their burglar masks behind the curtain, and this random woman comes and shoots Milverton in the face and then grinds her heel into his face. It’s odd, isn’t it? So I mean really, it’s just an extrapolation of saying, ‘Well, he probably did it, I think.’
Moffat: If Sherlock Holmes decided that somebody should die, he would kill them. I don’t think he’d have any problem with that.
Gatiss: He regards Milverton as a sort of plague, something that should be eradicated.