The Adventure of the Clapham Cook - S1-E1
Corrected entry: When Miss Lemon was putting up the frame on the wall, Hercule says "one centimetre to the left". I don't think that metric was invented yet.
Cat Among the Pigeons - S11-E2
Corrected entry: At 50':21" running time, there is a sudden flash on the actress's left eye, lasting only for a fraction of a second, seemingly from a camera flash or some other lighting equipment. (00:50:21)
Correction: This is just her eye reflecting the off-screen light. At one point, her head and eye movements catch a particularly bright highlight, which is exaggerated by the diffusion filter they are using. If it was a flash from the lighting equipment, you would see it in the lighting of the scene. (Not to mention, why would they be flashing a light in the middle of a shot?)
Correction: The metric system was first adopted by the French in 1795. Poirot is Belgian, and Belgium adopted it in 1816.
Jon Sandys ★