"Help me out, here: When Sherlock talks to Mycroft about his role in
Mycroft’s return to MI6, he says “I know you didn’t tell her.” This
confused me, given that we clearly saw Mycroft tell her. Is this is a
suggestion there is another detail about his involvement with the case
that Mycroft omitted? Or just a weird bit…

"I kind of like the idea that there wasn't anything else to his death. He
went back to using, and he died. Seeing Sherlock struggle with
accepting the idea of a relapse and trying to "solve' Allistair's death
made for some very good viewing, and some typically great acting from
Miller."

Perfect review. (Well, my sentiments exactly, at least.) Thanks.

Great commentary. The showrunners of this thing have set themselves a truly daunting task with juggling the procedural format — which I think functions just as you say in drawing in casual viewers — with the psychological origin myth that is their real interest and the real interest of the show's long-running fans.