Watson's words sting, particularly when that's precisely what he's been telling himself since the criminal got away. This illness, though -- he can't even wish this on himself, and it hurts that Watson apparently does. His head throbs again from the pain, and his leg involuntarily moves away from Watson's touch, and he doesn't even try to keep it still. It's his small, sickly form of rebellion.

"Is that your professional opinion?" he murmurs, aware it isn't the best comeback, but his mind is dull, and his pain and guilt are real. He doesn't need Watson to remind him of them.