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)
The Sins of the Father - S4-E9
Factual error: A character is revealed as having been hypnotised into committing murder against their will. This is not possible. (00:05:20)