Other mistake: When Bowie and his men first enter the Alamo, Travis calls for the colors ceremony and the detail marches to the flagpole. One section is ordered to "halt", then the order "about face" is given. However, the detail does a "right face" instead.
Other mistake: During the final assault, a man falls mortally wounded on a cannon wheel and shouts for Crockett to come over. Crockett is standing doing nothing with Beekeeper, in an action in where the defenders are largely out numbered. Shouldn't every man be fighting not standing around watching?