This episode was meant to be shown earlier in the season. In 'Ancient, Chines, Secret', Backstrom was already wearing the same pedometer that Dr. Chaman gives him for the first time in this episode. At the end of the previous episode, he even made a remark about the number of steps the doctor told him to take; a conversation which actually occurs during this episode.
The bedroom door behind which the possum is waiting, is a double door. When Backstrom opens the door to look into the room, it appears as though there is only a single door, and that they used a different doorway for the interior point of view. However, on closer inspection, the door to his right is actually just obscured by the bedroom wall.
Dr. Bai tries to establish his innocence by stating that Tad Taymor is in the control group of a clinical drug trial. Clinical trials are double-blind, meaning that neither the patients nor the doctor knows which patients are in which group.
Backstrom acts surprised that his doctor's first name is Deb but in the first episode, he makes fun of the doctor, saying he has a girl's name.