Continuity mistake: Saigo is told to empty out the chamberpot because it is full. But it is not full when he is taking it outside to empty it.
Factual error: When American Cosair fighter planes strafe the Japanese soldiers with their machine guns, only two columns of bullets are seen striking the ground. These planes had six machine guns; there should be six columns.
Continuity mistake: When the plane lands in the pouring rain and the soldiers gets out of the plane, you can see their jackets are already wet from previous takes.
Continuity mistake: There is a scene when Saigo and Shimizu are talking about surrendering and the camera cuts back and forth between the two and their head positions keep changing between cuts.