Whoops! Found this in my queue. Must have sent it to the wrong place. Sorry, anon!
Oh gosh, anon, you aren’t alone.
All the versions of ‘how he did it’ are framed, in the episode, in ways that run from clearly false to dubious. The Lazarus solution has the most credence of any of them, coming as it does from Sherlock, but then it’s questioned in the narrative too, leaving us confused as to whether we’re supposed to be believing Sherlock or Anderson.
So you’re totally in your rights to be confused, and you’re far from the only one. I’ve got several followers who don’t think the Lazarus solution is the real one.
I have been told that Moffat and/or Gatiss have said somewhere that the Lazarus solution was supposed to be the true one. But I don’t think I’ve seen that article for myself, so I can’t tell you for sure whether they did.
I have seen articles, like this one, where they played coy and wouldn’t say for sure whether any of the solutions they gave us were the true ones. Which is kind of frustrating, and not really the best time to be pulling the “we leave it open to your interpretation!” card.
One thing about the Lazarus solution, though, is that the only actually batshit thing about it is the ridiculously elaborate execution. But almost every possible solution would also require a ridiculously elaborate execution, so having a ridiculously elaborate execution is a point on which we’re required to suspend disbelief.
Aside from that, the snipers and all do make sense. Sherlock knew John was being threatened (naturally, since Moriarty has used him as a favored target before), so it’s reasonable that he would have laid plans to protect him. He seemed surprised about Mrs. Hudson and Lestrade, however. So even if there were plans in place to protect John, it’s possible there were not contingency plans in place to protect the two of them at that moment. So Sherlock would indeed have had to fake his death until the two of them were safe.
As for the emotions, the answer there could quite simply be that Sherlock doesn’t like to do things by halves. He might’ve been acting. Or maybe he was genuinely upset at how badly he was about to freak out John.
Fundamentally, though, the purpose of it all in the narrative was to do stuff the writers thought was cool. This is a thing about how Sherlock works: Sherlock’s abilities are magic. I mean that in the fantasy lit sense. We are given a loose rationale as to why they work, and then they do (within certain limitations) whatever the writers want them to do.
So the dark secret is that this show has never particularly made sense. It operates on the Rule of Cool: if the writers thing a thing would be cool, then they will handwave the question of how logical it is in favor of the coolness, and explain it with “because Sherlock.”
What most of us have always thought without really noticing is that we are okay with this, so long as the narrative of Sherlock and John’s evolving relationship continues to make sense. Which is the problem with the two year break, and season 3. The narrative we’ve been given for those simply doesn’t seem to jive.