Trivia: Unusually enough for a television show devoted to a homicide detective and the way he unravels the plans of cunning murderers, the fact is that Columbo has nothing to do in this episode. Doctor Collier is seriously assaulted by Carl Donner who then goes on to violently attack his wife. Use of deadly force to prevent such an attack is allowed in the United States. Collier does not commit murder; he doesn't even commit a crime. You'd think such a hightly educated man would know enough to keep his head, call the police and explain what had happened. He wouldn't even be charged.
Trivia: The flight attendant Monk drives crazy in 1-13 is played by his real-life wife. She also plays Sheriff Butterfield in "Monk visits a farm"and the crazy cat lady in 8-14.
Trivia: Johnson's script originally featured an ending in which Jesse loses the game and yet finds himself still alive. Seeing this, Fats explains that he will die "as all second raters die: you'll be buried and forgotten without me touching you. If you'd beaten me, you'd have lived forever." This ending was eventually filmed when this episode was remade in 1989, during the first revival of The Twilight Zone.
Trivia: Sharon Lawrence plays Sasha Alexander's mother in the series, even though in real life she's only 12 years older than Alexander.
Trivia: Originally, Batman villain Two-Face was going to appear in this show and was going to be portrayed by Clint Eastwood. Two-Face's backstory wouldn't have him as an attorney who had acid thrown in his face but instead have him as a news anchor who would have a stage light exploding resulting in his injuries and his transformation into a criminal.
Trivia: (POSSIBLE SPOILER) When Masuka brings up the list of doctors authorized to get the M99, Dexter removes his alias note that Dexter's fake alias (used to get the M99 tranquilizer) is Dr. Patrick Bateman. Patrick Bateman is the lead character of "American Psycho". This was most likely an intentional "easter egg" of sorts within the show.
Trivia: At around 5 mins 11 seconds into the episode, Vincent Nigel-Murrey and Dr. Saroyan are discussing the bones on the forensic platform. In the background of a shot of Vincent, the x-ray on the screen is of Homer Simpson's head in the middle of the screen, instead of a real human skull.
Trivia: Castle's Halloween costume is of Malcolm Reynolds, played by Nathan Fillion in the short-lived TV show "Firefly." Alexis asks him: "Didn't you wear that like five years ago?" Serenity, the film based on Firefly, was released 5 years before this episode aired.
Trivia: There is a scene in this episode where Walter angrily tosses a box of pizza in the air in such a way that the pizza exits the box and lands on his roof. Before filming this scene, the crew had wondered how many takes would be required to achieve the desired result. Bryan Cranston nailed it on the first try.