Errors made by characters (possibly deliberate errors by the filmmakers): During the dinner at the Teheran Conference, Stalin tells Churchill that in Britain there are two parties, while in the Soviet Union there is only one. In fact, Churchill's Coalition government included three major parties, not two: Churchill's own Conservatives, Clement Atlee's Labour Party, and Sir Archibald Sinclair's Liberal Party. Both were in the Cabinet: Atlee was Lord Privy Seal and member of the War Cabinet; Sinclair was Secretary of State for Air.
Anachronisms: Distance shots of Moscow show modern road vehicles
Anachronisms: On the table at one of the conferences there are miniature flags of the three powers. The U.S. flag used is the fifty-star flag, which did not exist until 1960.