The Ministry of Virtue - S14-E6
Continuity mistake: Around the middle of the episode, Hart and Carmichael walk down a street with ice cream cones in their hands. When they stop for a brief face to face discussion, the ice cream in the man's hand keep changing from full portion to half-eaten and vice versa as the camera perspective switches back and forth.
Suggested correction: The show is set in the early 1900's, which is the early 20th century. By the time this event transpired, SOS would have been established as a universal distress signal.
The show starts in 1895 and by season 2, it was still the 19th century and before Germany adopted SOS in 1905.
Bishop73