Revealing mistakes: In the Himalayas, a shot of a running soldier's foot clearly shows sand, not snow.
Continuity: Just before the battle at the temple bridge, Rick has a Thompson Sub-Machine Gun loaded with a 50-round drum. When the battle begins, the Thompson has a 30-round stick clip.
Factual errors: They fly to the Himalayas in a Beaufighter, a WWII single-seat fighter and bomber, not a transport aircraft. The plane has the color scheme and code markings of a Royal Australian Air Force Beaufighter that served in the South East Asia Command, which included India, Burma, and Southern China.
Anachronisms: During the 1947 Chinese New Year celebrations, a black Dodge four-door sedan has hubcaps from the late 1970s.
Continuity: When Alex and Lin are under the emperor’s wagon during the chase, we see Alex turn himself around, get dragged on the street for a fair distance while Lin tries to reach him to pull him up off the road. As she succeeds we see the back of Alex's shirt is shredded, and a protective pad can be seen through the tears. In the next shot his shirt is whole again, suspenders and all.
Anachronisms: The drum set featured in the nightclub scenes is a modern set, rather than one from the 1930's. Some of the hardware (cymbal stands, etc.) in this set was not available until the 1980's.
Anachronisms: The dancing girls in the nightclub have plastic straps on their bras.
Factual errors: In ancient China, oracle bones were turtle shells that were heated during divination, the cracks that appeared across Chinese characters written on the shells were then interpreted to foretell the future.
Errors made by characters (possibly deliberate errors by the filmmakers): When on the mountain, Rick said he had more experience with mummies. Alex says that it was only one. Rick says it was twice. But, in 'The Mummy Returns', he kills the original mummy, and the Scorpion King, making a total of 3 mummies.
Continuity: When Evelyn discovers the bullet in the trout she pulls it out of her mouth. In the next shot of the left side of her face she is pulling the bullet out again.
Factual errors: The bullet which Evelyn pulls from her mouth has a compressed shape, as though it had struck a solid object. A close-range shot would likely have passed straight through a trout.