Favorite Son - S1-E6
Continuity mistake: When Dan confronts Mazikeen over leaving him in Chloe's apartment, he has his arms outstretched in the front shot and down by his side in the reverse shot. (00:21:20)
Sweet Kicks - S1-E5
Continuity mistake: The position of the guys Mazikeen attacks changes between shots. Note the woman Chloe knocks out. (00:31:30)
Lucifer, Stay. Good Devil. - S1-E2
Continuity mistake: When Lucifer shows his devil face to the preacher at the start, the mascot behind Lucifer changes between shots. (00:03:00)
Sweet Kicks - S1-E5
Continuity mistake: When talking to Benny about his pig being killed, Benny's hair is constantly changing from neat to scraggly and back. (00:24:30)
A Priest Walks Into a Bar - S1-E9
Visible crew/equipment: When Linda is talking to Lucifer a white screen is reflected in her glasses. This can't be the window as the window is behind her. (00:03:30)
Visible crew/equipment: After the brief discussion in the hallway outside Linda's office, as Lucifer walks off a green screen is reflected in her glasses. (00:11:50)
Favorite Son - S1-E6
Visible crew/equipment: When Linda and Lucifer are having a discussion at the end, a light screen is reflected in Linda's glasses. (00:39:10)
Favorite Son - S1-E6
Continuity mistake: Near the end, as Lucifer is bearing down on the biker asking who took his wings, the Biker stumbles and has both hands behind him. When the shot changes his left hand is raised. (00:33:40)
Favorite Son - S1-E6
Revealing mistake: When Lucifer is going through the forensics bag next to the dead body at the start, the body of the victim can be seen breathing. (00:07:30)
Favorite Son - S1-E6
Continuity mistake: At the start when the security guard is attacked, the number of papers thrown about changes from 5+ to 3. (00:02:40)
Sweet Kicks - S1-E5
Visible crew/equipment: When sitting down in The Paddock Bar, the man next to Lucifer is wearing glasses that reflect a light screen. (00:12:30)
Sweet Kicks - S1-E5
Continuity mistake: When Chloe and Lucifer get in the car to go to a bar, the car's position in the alleyway changes from the street level shot and the overhead shot. Note the position in relation to the plant by the side of the car. (00:12:10)
Continuity mistake: At the start when Trixie comes running in to give Lucifer a hug, Lucifer has got a jar in his hand. As the shot changes to him actually being hugged, the jar simply vanishes from his hand. (00:03:05)
Visible crew/equipment: When Chloe shuts the door on Dan, a stage light is reflected in the glass of the door. (00:04:10)
Factual error: The record producer is holding a pistol model 1911 or 1911A1 which is a .45 caliber handgun with a standard magazine capacity of 7 +1 rounds, the +1 being loaded in the chamber, however newer magazines hold 8 +1. Therefore, this handgun can hold a maximum of 9 rounds, however the producer fires 10 shots before Lucifer grabs him. Newer 1911 style pistols are now produced in 9mm which have a greater capacity but the pistol held by the producer was a standard 45 ACP judging by the metal and finish. (00:37:38 - 00:39:18)
Answer: Boo Normal and Once Upon a Time were going to be part of season 4, then the show got cancelled (before being picked up elsewhere). As such they were added on to the end of season three as "bonus" episodes, hence the continuity being off. But not really a mistake, just a quirk of broadcasting. Boo Normal was originally going to be between the episodes "High School Poppycock" and "Infernal Guinea Pig" in season 3 before being slated for season 4, presumably because aside from the point you've raised, it was fairly flexible, continuity-wise.
Jon Sandys ★