Revealing mistake: When the Muslim emissary arrives to Jerusalem and Guy de Lusignan stabs him under the chin, look at the blood. It bursts from something attached to his shoulder. In addition, the emissary is seen as stabbed with a small dagger but then Guy De Lusignan is shown holding a full length blood tipped sword a second later.
Revealing mistake: As Uchida makes his last-stand the ships tilts heavily to the right, however none of the empty shells on the deck move, showing that it's only the camera being angled.