The Daughter of Autolycus - S4-E5
Other mistake: Lady Felicia says "Ah, Father, how very propitious." The subtitles say "Ah, Father, how very capricious." (00:03:10)
Father Brown (2013)
1 other mistake in season 4
Starring: Mark Williams, Nancy Carroll, Alex Price, Sorcha Cusack
The Curse of the Aesthetic - S8-E8
Continuity mistake: When the nanny is found dead, the ball of wool in the bag is yellow but later on when Father Brown picks up the wool out of the bag it is grey.