Fiske's horse disappears when they take refuge on the mountain track.
When Hooker hits Daly while camping in the mission, Daly falls on his back. In the next shot, he rolls in the fire. However, when he falls in the first shot, he clearly falls further away from the fire.
The film is set in Mexico and the Indians are being called Apaches. However, they are dressed as Northeastern American Mohawks. In addition, the men of the Apache nations were traditionally long-haired. In this film, the "Apache" Indians are sporting Northeastern Mohawk haircuts.
As true Apache warriors usually wore their hair long, the mohawk-sporting "Apaches" in this film would more likely have been the mestizo descendants of Pawnee Indians captured and enslaved by Apaches.
The firearms being used belong to the period from about 1870 to 1880. If this film was set during the California gold rush period of 1849 the weapons should all be percussion cap and black powder. Repeating rifles weren't developed until late in the Civil War.
The Steamboat that landed Hooker and Fiske on the shores of Mexico is of early 20th century design and definitely not of the gold-rush days of 1849.
Imprinting through the back of Leah Fuller's (Susan Hayward's) blouse is a modern-day brassiere. The story is set in the mid-nineteenth century, but the earliest modern bra didn't become widely available until the early twentieth century.