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 the soldiers are ambushed by the Germans, they jump off and Jack Kelly is wounded in the arm, showing a torn shirt and bloody arm. Later when Audie Murphy is wounded and in the hospital Jack Kelly visits him. The only bandage on him is on his hand, which wasn't injured before.
Continuity mistake: In the scene where Trevor Howard and José Ferrer are sharing what appears to be some port (about 50 minutes into the movie), the port decanter has a drip stopper in the long shot which disappears in the close-up shot of Leslie Howard and then re-appears in the following longer shot.
Continuity mistake: Wallis is showing his idea to the doctor and draws on the sketch of the dam. Shortly after, he shows the doctor the same sketch again and the middle line we saw Wallis draw has now changed position. (00:06:40 - 00:07:50)