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.
Revealing mistake: In the close-up of Frost's hand while the doctor is stitching up his wound, you can see the delineated edges of the latex make-up patch used to simulate the injury. (00:12:30)