The role of Coral Chandler was originally intended for Rita Hayworth, but she had already been cast by her estranged husband, Orson Welles for the role of Elsa in The Lady from Shanghai (1947).
In the train scene, after they discover that Drake is to receive the Medal of Honor, Murdock quips that maybe the president will let Drake "sit on top of his piano". This is a reference to a then-scandalous photo of Harry Truman playing piano with a leggy blonde on top that was taken at the National Press Club in 1945. The blonde was Lauren Bacall.
After Murdoch tells his story to the priest, he leaves the church, and as the priest looks at the open door the rain starts up, haltingly, the obvious product of a garden hose.
Carla mentions it has been two days since she last saw Johnny. Night comes. People sleep. Day comes. Carla says it has been two days since she last saw Johnny. Should be three now.
Captain Warren 'Rip' Murdock: [coming to from a drugged stupor]
Coming out of it was like after being tapped on the button. Everything foggy - fur in my throat, an anchor on my head, and ringing in my ears.
Captain Warren 'Rip' Murdock: I hated every part of her but I couldn't figure her out yet. I wanted to see her the way Johnny had. I wanted to hear that song of hers with Johnny's ears. Maybe she was alright. And maybe Christmas comes in July. But I didn't believe it.