I saw this episode fairly recently, so when I went back to read the original story, I was struck by the changes made for film, particularly that Holmes in ACD doesn't connect the beating Isadora's thugs give Douglas with his untimely death.

I also found it interesting that instead of having Douglas die abroad, we get to see him at his grandmother's house writing passionately through his pain out in the gazebo. While this certainly makes it clear that Isadora is directly responsible for his death, it makes the timing of the Dixie's attempted intimidation and the subsequent break-in messier, since the manuscript is always at the house and not recently-arrived with his personal affects.

While I like that the directors were focused on making Holmes see what he doesn't in ACD (because what film/TV version of Sherlock Holmes isn't obsessed with making Holmes seem superhuman?), it's true, his relationship with Watson suffers for it. Thanks for the perspective!