Continuity mistake: In the scene where the Reluctant is in the port of Elysium and the men are on shore leave, a truck load of MPs show up. Ttheir patrol leader tells Mr. Roberts that his men will be stationed along the starboard side of Mr. Roberts ship for the remainder of its stay in port because of the problems various members of the ship had been causing while on shore leave. No sooner do the MPs line up along the side of the ship do you see one of the ships crew flying down the dock on a motorcycle. When the motorcycle passes the ship the MPs who just 10 seconds before were lined up along the ships starboard side are now nowhere to be seen.
Continuity mistake: When Frank gets his mail, he first reads out loud the letter from Doug, but then the next letter says that Mister Roberts, Doug, is dead. Depending on the cameras' viewpoint, the letter is crumpled, then not, then crumpled again before Doc takes it away from him.
Continuity mistake: In the opening scenes, Mister Roberts is sitting on the deck of the ship with a folded piece of paper in his hands, but when Doc approaches, the paper is now unfolded.
