Factual error: Nick says that she made the will 6 months before the events of the episode, just before her appendix surgery. The surgery happened on February 27th, so it would be the end of August now. But at the beginning of the first episode Hastings was reading a (movie prop) copy of the Daily Express which had on the cover "Perry makes a new record - Champion two years in succession", complete with a picture where he is unmistakably with his rival Gottfried Von Cramm. The photo (and the mention of the 2 years record) is about the Wimbledon final who took place on 5 July 1935. That's almost 2 months earlier than it should be. (00:04:45)
Factual error: Jim Lazarus drives a Vauxhall DX (14/6 Light Six) Stratford Tourer, a 1936 model. This episode takes place in the summer of 1935. (00:46:20)
Factual error: Poirot has just suffered "a turned ankle", in his words; he's talking with Hastings and the kind woman who helped him out, when their conversation gets perturbed by the noise of a plane. Which is surprising, since the plane in question is a Volmer VJ .22 Sportsman, a plane from the 50s, way after the 1930s setting of the episodes. (00:06:40)
