Holmes telling a client who is concerned about her safety with her new employer that she just has to send him a message, any time day or night, and he will come and help her. And a few pages later Holmes says that the isolation of country houses makes him uncomfortable, because he knows that it’s easier to commit domestic abuse and go undiscovered in those isolated homes.
This is what I’m talking about when I call him a social justice warrior and say that he cares most about marginalized people. If you think no one cares about you, Sherlock Holmes cares. And he will do what he can to prevent violence against you or to stop humiliation from befalling you.