Factual error: The watch that Sid sold (a gift from Father Brown) appeared to have a twist-o-flex band, but they were not available until 1962.
Factual error: Mrs. Devine's Morris Minor is a 1962 model, this series is set in 1954.
The Crackpot of the Empire - S4-E4
Continuity mistake: When Eve gives Jacob a ride in her car, she says "Sorry for the bare feet, I can't drive in heels." She has no nylons on. When they get to the old building, Eve gets out of the car wearing black nylons and heels.
The Great Train Robbery - S7-E1
Factual error: The newspaper shown at the end, dated 31st of August 1953, has an article in it called "Enemy Claims" about the German campaign on the Balkans in 1941. (00:42:55)
The Sins of the Father - S4-E9
Factual error: Lady Felicia is asked to sing a song she would sing in church and chose "Morning Has Broken," most lately associated with Cat Stevens, but here's the catch: Prior to Cat Stevens' rework of the 1931 English children's hymn's lyrics (by Eleanor Farjeon) to the tune of old Scottish children's hymn sang in the old Gaelic: "Child in a manger, Infant of Mary, " based on a melody called "Bunessan" (written by Mary MacDonald), the 2 hymns' lyrics and tune weren't combined into the one hymn until 1972. (00:05:00)