In both the movie and "Stargate SG-1", Catherine was not aware of the Stargate's function, how dialing the glyphs opened the gate, or the fact that a sequence of seven symbols was necessary.
In scenes situated in the gate room of Aset's temple, the curtain revealing the sky and the three moons is alternately open and closed within the same sequence.
10:27 The battery cables to the gate are simply wrapped around the terminals but there are no cables to the generator or the vehicle, so running either will not charge the system.
7:56 When Catherine is loading the revolver, all of the cartridges have been shot as the primers are all struck.
The Kubelwagen registration number is non military. An army one would start "WH" whilst one in service with the SS would start with the "SS" runes.
The wooden platform going through the gate should be vaporized when the gate is activated.
The movie shown by the Nazis to the Goa'uld shows the French troops in the Maginot line surrendering and other battles in France, this movie is supposed to be set in 1939, France wasn't invaded by the Germans until May 1940.
The film is set in 1939. The Kubelwagen is painted in "Normandy camouflage" that wasn't introduced until late 1943.
The film is set in 1939. However, the Kubelwagen, MP-40 sub-machine gun, and the Walther P-38 pistol were not manufactured until 1940.
When Catherine and James are arguing after she pushed Wasif into the just opened Stargate, James asks "Whatever happened to ladies first?". Modern feminism not withstanding, a British officer of the WWII era would be well versed in Gentlemanly etiquette which states that in times of dangerous or unknown circumstances the man 'should' always precedes the woman so that if some mortal danger arises then the woman is not exposed to it first.
Beal tells Catherine that, if hadn't been for the artefact, "Our chance encounter may have never come to pass." A British person would have said "might have never". In British English, using 'may' suggests a possibility that it didn't happen.