Sherlock glances at Ted, and there's guilt and sadness in his eyes. It's a vulnerable, raw moment for someone whose default is to shut people out. He looks back at Watson. He absolutely blames himself. He should have realized the narcotics agent was the kidnapper. And that the waiter was the poisoner. Both times Watson paid a price for his misstep. Both times she could have died. This time she nearly did.

"It was after that that I first insisted Watson learn a few methods of self-defense. Especially since it was likewise shortly after that that she became under my tutelage and employ."