In the opening scene at the restaurant, Philip Bartel (Dan Dailey) tells his friend Peter Harding (Howard Duff) that his mistress Lorna Dickson (Bettye Ackerman) is 28, and Harding reminds Bartel that his wife Beatrice (Jan Sterling) is 38. In reality, Bettye Ackerman was 38 while Jan Sterling was only three years older at 41.
In his closing monologue, Alfred Hitchcock includes a disclaimer that the poison used in the plot, 'Altrapeine', is fictitious and does not exist. The "poisons" used in many other episodes of the series were also fictional.