Continuity mistake: During the party, Stass the assassin, dressed as a waiter, hides his gun underneath a stack of white napkins. When he gets ready to pull the gun out, it is now between the napkins.
Continuity mistake: In the opening scene when John is going to the refrigerator, a white skull can be seen on the left side of the kitchen table amongst all Sherlock's science equipment. When he closes the refrigerator door again after discovering the severed head, the skull has disappeared. As he's leaving the kitchen, the skull reappears. (00:03:25)
Continuity mistake: During the stakeout of the apartment building, in the exterior shots of the Clyde Motorcycles shop, Danny is peeking out through a ripped paper opening within the letter "D" in Clyde. However, in the interior shots the black tape letters of the word Clyde differs. The paper is ripped between the two letters "D" and "E" and that space within the "D" is blocked with molding, making what is in the exterior shots quite impossible. (00:15:40)
She Works Hard for the Money - S1-E4
Continuity mistake: Jane shows the photo of the victim Danielle to her old contact. She holds the photo differently, either above its left corner or below it. (00:22:15)
Continuity mistake: As Arlo Givens strikes Hunter Mosley with the hair clippers, the clippers are pointed upwards at first, but after the blows, they point downwards. (00:07:35)