Factual error: The El Paso newspaper is dated Monday June 15 1872. June 15 1872 was a Saturday. (00:48:14)
Factual error: The second blackmail message from SPECTRE tells the British that they must drop the ransom diamonds in a container "off the coast of Burma, in the Mergui archipelago, latitude 20 degrees north, longitude 60 degrees east." Unfortunately, 20 N, 60 E is nowhere near Burma. It's right off the coast of Oman in the Arabian peninsula, all the way on the other side of India from Burma. The actual coordinates for the Mergui archipelago are approximately 13 N 97 E. I guess there wasn't a map handy....
Factual error: When an older lady working for the German cause is collecting items from the US Soldier's room (Garner), she picks out a letter with stamps on it that were not issued until 1954 and 1961...even though the year of the movie and scene is only 1944.