Robert Mitchum told Roger Ebert he smoked so much that when the camera was rolling and Kirk Douglas offered him a pack and asked, "Cigarette?" Mitchum, realizing he'd carried a cigarette into the scene, held up his fingers and replied, "Smoking." His improvisation saved the take and they kept it in the movie.
Jane Greer recalled that the laconic Robert Mitchum projected an equally cavalier attitude off camera. She got the impression that he came to the set unprepared, in order to give a more spontaneous performance. She explained, "I remember him saying 'What are the lyrics?' to the script person. 'I never know the lyrics,' he'd say, and she would give him the lines. I said, 'You don't learn your lines beforehand?' and he'd said, 'Naah.' Gosh, I learned mine a week ahead of time. I thought that might be part of why he seemed so much more spontaneous, why he was so easy and underplayed. I decided I'd do that, not be letter-perfect. So I tried learning my lines under the dryer in the morning. I hoped I'd look as though I was thinking. But I blew take after take, and he was letter-perfect. Well, I figured out later that, of course, he knew the lines."
On November 14, 1987, Robert Mitchum was the guest host on Saturday Night Live (1975), broadcast from the NBC Studios at 30 Rockefeller Plaza in New York. One of the sketches he participated in was a black-and-white spoof of the film called "Out of Gas." The sketch featured an unbilled guest appearance by none other than Jane Greer.
At age 15, Jane Greer was struck with facial palsy and lost all movement on the left side of her face. She gradually recovered, but it has been speculated that this contributed to her "patented look" - an enigmatic expression that would later lead RKO to promote her as "The woman with the Mona Lisa smile."
After Humphrey Bogart refused the lead it was offered to John Garfield and then Dick Powell, both of whom turned it down. Robert Mitchum was fourth choice.