A Priest Walks Into a Bar - S1-E9
Continuity mistake: The position of the priest after he has died changes between when Lucifer walks over to the other person and when Connor walks over to the priest. (00:35:00)
A Priest Walks Into a Bar - S1-E9
Continuity mistake: At the end on the balcony Lucifer's cigarette switches hands between some instant cuts. (00:36:30)
A Priest Walks Into a Bar - S1-E9
Continuity mistake: When Malcolm asks Amenadiel if food tasted this good before he died, his hands are clenched into fists with one finger pointing at the food. When the shot changes his hands are open and just facing forward. (00:39:20)
Continuity mistake: At the very start of the episode, the strawberry that the woman bites into changes shape several times between shots. (00:01:30)
St. Lucifer - S1-E11
Continuity mistake: The way Malcolm holds the gun when showing it to Dan changes between shots. Note his grip. (00:06:30)
St. Lucifer - S1-E11
Continuity mistake: Just after saying the widow could hold the charity event at Lux, Lucifer has his hands clasped. As the camera changes angle changes however his hands are apart. (00:07:30)
St. Lucifer - S1-E11
Revealing mistake: When Chloe is getting dressed at the start of the episode, she is wearing a flesh colored bra underneath the bed covers that she has wrapped around her when she mentions her ex dumping her by text.
Continuity mistake: At the start, the man's hands change position around the woman during instant cuts. (00:01:40)
Character mistake: When trying to decipher what the letters from the dermal implants spell, Lucifer rearranges the letters and says "Hilii Fircus, it means 'children of the goat.'" However, the correct phrase was Filii Hircus, not Hilii Fircus. (00:13:27)
Continuity mistake: When Onyx opens the box, the way he holds the lid changes between shots. (00:19:50)
Continuity mistake: In the scene in the warehouse, Chloe and Lucifer end up right below where Corazon is tied up. Then blood drips on her hand prompting her to look directly above her head. In the next shot Lucifer turns around and suddenly they're both meters away, looking at the contraption from a distance. (00:26:50)
Continuity mistake: When Chloe turns the picture of the cufflink upside down to Dan, her grip on the photo changes between shots. In one, she has one finger behind the picture, but in the front angle, all of them are at the front. (00:33:10)
Continuity mistake: When Linda asks Amenadiel if he is a real doctor, he has both hands raised. Camera cuts and now he only has one raised. (00:08:20)
Continuity mistake: When Lucifer helps Amenadiel, who has been stabbed with one of Mazikeen's daggers, Lucifer has one hand on Amenadiel and one by the dagger. The camera cuts, and now he has both hands on Amenadiel. (00:21:45)
Everything's Coming Up Lucifer - S2-E1
Visible crew/equipment: When Lucifer and Chloe are walking across the set at the start, the camera rig is reflected in the car's paintwork. (00:05:20)
Everything's Coming Up Lucifer - S2-E1
Continuity mistake: When Lucifer and Ella are talking for the first time, Ella's hair changes from neat to messy between shots and back again. (00:08:50)
Everything's Coming Up Lucifer - S2-E1
Continuity mistake: When Lucifer walks out of the police station having worked out who Bobby B is, Chloe has nothing in her hands in one shot, and a piece of paper in the next. (00:30:40)
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 ★