The green bathroom where the victim's body is discovered is modelled after the setting of the bathtub scene in The Shining (1980).
Sorbet: A frozen dessert made from sweetened water and flavouring.
At the murder scene, the moment when Graham bluntly shuts the door on Zeller, a determined wannabe expert, parallels the moment when Sherlock excludes wannabe expert, Anderson, from his crime scene in A Study in Pink (2010). Great detecting minds both misbehaving impolitely alike.