Edward Mordrake: Part 1 - S4-E3
Deliberate mistake: After Elsa kicks Bette and Dot off the stage, Elsa looks at the sheet of music on the stand and you see the name of the song 'Criminal' and it also states it's by Fiona Apple which is true, but this season is set in 1952, and Criminal wasn't released until 1996.
Deliberate mistake: Conjoined twins Bette and Dot have freckles and moles on their faces and necks in the exact same places.
Suggested correction: Not technically a mistake; unlike regular twins, conjoined twins are always identical in appearance, contrary to what movies/TV suggest. This could easily include mole patterns.
I looked up "conjoined twins" on Google images, and there are numerous photos of conjoined twins having freckles and moles in different spots. Notably on the Hensel twins, Brittany has a mole on her chin, but Abby does not. This disproves your suggestion that conjoined twins are always identical in appearance and could have identical mole patterns.
