Near the beginning of the movie at the start of the carriage chase, Robert Taylor lowers the carriage top. When the scene cuts to the next camera angle he is seen to lower the top again.
When Mark Brandon (Robert Taylor) finds the unopened sealed door to the tomb, the bottom edge of the pivoting door as outlined in the wall is about a foot above the ground level. However, after he swings it open with his pick, the bottom edge is about two feet up and there is another stone about a foot wide in the bottom center of the doorway that he pushes out of the way so they can walk in stooped over under the door.
Eleanor Parker runs from a tree after Robert Taylor puts a cape on her, but after a cut a person with the same cape is again seen running from the tree.
Before the desert sandstorm, a rabbit is shown crouching beside a clump of grass, with a tile or flat square stonework nearby. After the storm, there are different shots showing how the sand covered things over... except for the rabbit, the clump of grass, and the flat stonework.
The use of the word "corn" is not an anachronism. Corn was a common term for wheat in the Old World, centuries before Columbus. Native American maize was called "corn" by the Europeans because it was a familiar term for this new staple grain. Even today corn is used to refer to crops such as wheat and barley in British Common Wealth areas of the world. In America all of these would be referred to as "grain".
During the sand storm, the wind is strong enough to blow Ann off her feet, however both Ann and Marks hats stay on. During the sword fight Mark's hat falls right off.
The opening screen tells us the year is 1900, After the events at Abu Simbel, Ann and Mark take a boat down the Nile. Mark, and the camera, take particular note of the flooded ruins of the Temple of Philae. This site wasn't flooded until the completion of the Aswan Low Dam in 1902.
Near the end of the movie, inside the inner tomb of Ra Hotep, Robert Taylor reads an inscription that mentions a seven-year drought affecting the corn crop. Corn is native to the New World and would not have been present in ancient Egypt.