Character mistake: In the 11/14/2005 US Army Rangers report about Peter MacLeish, the word captain right under MacLeish's signature is misspelled "captian."
Chapter Four: The Moveable Feast - S1-E4
Audio problem: When Father Keane is speaking with Mother Bernadette outside, when Mother Bernadette says "The gift doesn't reside in you or me", and "Where you coerce and compel, we use compassion, forgiveness, and patience", her lips do not match what she is saying.
Factual error: The DI refers to the local policeman as "Officer" Fuller. No British police officer would use this term to refer to another British police officer. She'd have said Constable Fuller or PC Fuller.