The punch line to the unfinished joke the loudmouth at the bar was telling (It's the mailman's last day on the job, he goes to a woman's house and she invites him in, makes love to him, makes him a wonderful breakfast and then gives him 5 dollars) is: Mailman: What was that for? Woman: Well I asked my husband what to do for you on your last day and he said, "Screw him, give him 5 dollars." The breakfast was my idea!
The script was considered for Twilight Zone: The Movie (1983) before Steven Spielberg was brought in on that project. The film would have consisted of only this story (instead of the four segments it eventually became) and would have had a slightly different ending with a Twilight Zone twist. Steve De Jarnatt did not like the change in the ending and the idea was eventually scrapped.
According to a story told by casting director Billy DaMota in the documentary I Don't Know Jack (2002), the role of Fred the Cook was originally offered to Eraserhead (1977) star Jack Nance, who refused the role because he wanted to focus on his day job as a security guard.
When the main character Harry is recounting his phone conversation to Landa, she asked him to repeat the launch code and then mentions the Rand Corporation and how someone who works there could know something about the launch code. The Rand corporation was a think tank formed in 1948 to advise the United States government on national security issues. Their most well known contribution being the doctrine of Mutual Assured Destruction (MAD) during the cold war.
Wilshire Boulevard was closed for two days for the filming of the climax. Moreover, Steve De Jarnatt had to shoot additional pieces for the climax at his own expense after principal shooting on the movie had wrapped.