Freddie Jones, who plays James McAllister is one of two actors to appear in both the original and the remake of Randall and Hopkirk (Deceased). He was in the episode Revenge of the Bog People in the remake. (The other actor who appeared in both versions is Dudley Sutton.)

Marty's watchband, which is normally white, is black through most of this episode.

Marty calls Mrs. Pleasance by her name but he is never introduced to her or told her name.

It is obvious that Kim is not firing the gun when she shoots her husband.

Marty moves the curtain with his hand at Mrs. Pleasance's.

(After Marty finds a room behind the bookcase)
Marty: A plain room, no way out.
Jeff: A priest hole.
Marty: A what?
Jeff: A place where they used to hide during the Persecution.

In an edict in 1559, Queen Elizabeth I banned Catholic Masses. This led to a prolonged period of open persecution of Catholics. Houses and castles owned by Catholics had "priest holes" built in them where clergymen could hide. Church relics were also hidden; and, in larger priest holes, church services were conducted. The persecution continued through the reign of King James I in the early 17th century.

Jean-Claude: May I speak with you, Monsieur?
Jeff: Sure. Asseyez-vous.

Asseyez-vous is French for "have a seat" (literally translated: "you sit").