In the Sign of Three, we learn of a murder and an attempted murder in which the assailant had hidden an extremely sharp blade on the inside of a belt. The blade is so sharp that the victim doesn't notice the resulting wound, and does not bleed until the belt is removed, at which point he exsanguinates.
This is absurd, right?
In the case of the first victim, why did he start bleeding in the shower, and not when he disrobed? Are we to understand that he didn't take his belt off until he was already in the shower?