The inspirations for the film's costumes were Casablanca (1942) and Now, Voyager (1942), where the costumes combined both simplicity and beauty.
Gossip magazines with no credibility spread rumors of an affair between Marion Cotillard and Brad Pitt during filming, just like they used to do to all of Pitt's previous female co-stars. None of it turned out to be true though, but Angelina Jolie filed for divorce from Pitt only two months before the film was released, claiming that Pitt was violent toward her and their children. However, the fans of the couple turned their anger to Cotillard and blamed her for their divorce, to the point of sending her death threats, vandalizing her Wikipedia page and leaving insulting comments on her Instagram account, such as telling her to kill herself and abort her baby. Cotillard was pregnant at the time with her second child with longtime partner Guillaume Canet, but she hadn't announced her pregnancy yet. Cotillard, who was very private about her personal life and didn't have the habit to comment on rumors, was forced to announce her pregnancy and denied the rumors of an affair with Pitt. Jolie denied that Cotillard had anything to do with their divorce. Canet also defended Cotillard from the rumors. Pitt never said anything to defend Cotillard from the rumors nor from his fans' attacks. Cotillard was heavily pregnant during the film's premiere and press tour and had to answer questions about the affair rumors even on a live TV show, while Pitt was never asked about any of that.
While in bed waiting for the phone to ring, Max is reading the book "Brighton Rock" by Graham Greene. The plot involves a crime lord planning to marry the only witness to his murder of a journalist, much like the general theme of the film on betrayal and double crossing. Graham Greene is also famous for "The Ministry of Fear", another spy thriller set in World War II, in which an ordinary person is mistaken for a German spy after winning a pie (which contains a microfilm with military secrets) in a raffle.
This is Brad Pitt's fifth World War II movie, following Inglourious Basterds (2009), The Curious Case of Benjamin Button (2008), Beyond All Boundaries (2009) and Fury (2014).