Revealing mistake: When Bjornson is in Oslo he calls Catherine, who is still in Alesund, from a pay phone. But located behind him is a poster listing emergency numbers for the municipality of Giske, revealing that this scene was filmed there, just outside of Alesund.
I of Newton - S1-E29
Revealing mistake: Set lights are visible in the Demon's sunglasses while he is wearing them and when he is not.