Corrected entry: During the last attack, one of the cannons is turned around against the Mexicans that have breached the wall. We see it loaded with canister charge (random pieces of metal) instead of a proper cannonball or grapeshot. When the cannon fires, there are many Mexican troops lying on the ground. Canister charge is a gruesome weapon that causes a cannon to work like a giant shotgun and will reduce a human being to slivers of bloody flesh in an instant - there's no way the Mexicans could avoid being completely butchered. (01:46:30)
Corrected entry: In the scene where the Alamo is in full view, you can see the flagpole is flying an American Banner. In reality, the Texan Army used the Mexican flag, but with the numbers "1824" on it because it wanted the old constitution back that Santa Ana repealed.
Corrected entry: During the final attack, the Mexicans charge a corner of the fort guarded with wooden stakes set at an angle in the ground. As the Mexicans temporarily fall back, the stakes can be seen wiggling like rubber. Though it could be green wood, no defender would use green wood as a stake intended to stop attackers from charging onto it exactly because it would bend. (01:41:50)
Corrected entry: The first scene of the movie shows stone on the Alamo's wall marked as a calendar of the siege. There are 13 marks on the stone. The final assault takes place before dawn of the 13th day. So, the stone in the first scene should have had only 12 marks.