Volkswagen Kübelwagen is used in this episode however the episode is set in 1938 when the Kübelwagen was only put into production in 1940. Even the prototype Type 62 only first saw action or use in 1939 during the invasion of Poland.
Several Nazi guards are seen to be carrying late model MP40s lacking the 1938 models leather safety loop. Rather these MP40s have the cut out slot where the bolt is locked into place.
When the SS officer points a Walther P-38 at Catherine's head, the hammer is obviously back, but the trigger is in the double-action uncocked position.
When Catherine opens the revolver cylinder to check if it's loaded you can clearly see the primer on all the rounds of ammo have a dimple indicating they have been fired. Since she has not fired the gun there should not be a dimple on the primer on the rounds of ammo.
The opening scene featuring the discovery of the Stargate in Giza takes place in 1928. The next scene is accompanied by a subtitle "Ten Years Later." However, Professor Langford's telegram from Dietrich is dated August 22, 1939.