Revealing mistake: On the episode where Diana goes to New York and visits the hospital, it is filmed in the Reynolds Building at UMIST. Visible through the window is the Mancunian way with the car travelling on the left (not right) side of the road.
The Crown (2016)
2 revealing mistakes in season 4 - chronological order
Starring: Matt Smith, Claire Foy, Vanessa Kirby, Victoria Hamilton
Continuity mistake: During the photo shoot, after Tony takes the final shot and tells Margaret to "get dressed", so he can show her his place, she is wearing a different blouse and different earrings when she comes upstairs to his apartment.