Ian Fleming identifies himself as being with MI6. He was actually with the Royal Navy's Naval Intelligence Division.
The German SS uniform worn by Ian Fleming has conflicting insignia. The shoulder straps are those of a Hauptsturmfuhrer (Captain) while the collar title is that of an Obersturmfuhrer (Lieutenant).
The supposed V-2 missile is nothing like the real thing, as the real V-2 was much, much bigger.
Wernher von Braun is referred to by the German honorific Herr, meaning Mr, when by 1944 he held a PhD in physics, conferred in 1934, and should have be referred to as Doktor.
At several points we see German SS troops wearing black uniforms. The action is set in 1944 but Reichsfuhrer Heinrich Himmler withdrew the black SS uniforms from service in 1942.
At 32:00 during the Nazi gathering to view the launch, there is a quick shot of a bathroom sign showing "Men/Women" and the handicapped symbol that can frequently be seen in the US, not something found in 1940's Germany.
The setting is Germany in Dec. 1944. This happened to be one of the coldest winters in years in Europe, and not only is there no snow anywhere, but the trees are still nice and green.
References are made to the James Bond movies Skyfall and Never Seen Never Again, indicating that Ian Flemming would take inspiration for such titles. However, Skyfall was not based on any of Flemming's James Bond novels. Similarly, Never Say Never Again was a remake of Thunderball, and none of Flemming's novels were such named.
The truck hauling the Nazi V-2 rocket across the bridge in the forest is an American-built Heavy Expanded Mobility Transport Truck (HEMTT - pronounced "HEM-ett"), built by Oshkosh since 1981, and used by the US military starting in 1982; the camouflage pattern on the truck is also consistent with the original forest camo pattern available in the 1980s. The HEMTT is an eight-wheel-drive 10-ton cargo truck, with a distinctive cab which angles down and in, from the base of the windshield to the frontmost axle. There are several variants of the HEMTT, including fuel tanker, water tanker, firefighter, missile transport, trailer hauler, and more; though the full truck is never visible in a single shot, enough of it is shown to reveal it is either an M977-series or M985-series cargo truck; each of these variants has an available built-on crane at the rear.
No German would have addressed an SS officer as a Hauptmann (Captain). The SS had their own specialized rank system and the correct rank would have been Haupsturmfeuhrer.
Wyatt says they are on their way to Antwerp. In Dec. 1944, Antwerp was in Allied hands far behind the front lines so if a German said that it would have been a red flag to another German. Antwerp was one of the objectives for the German offensive that became known as the Battle of the Bulge. Speaking of which, it seems odd that Lucy never mentions it.
Fleming says that V2s rained down on London during the Blitz; Rufus berates Von Braun for developing weapon that killed tens of thousands: both are wrong. The Blitz was 1940-41, with a later offensive in early 1944 (Operation Steinbock, the Baby Blitz) while the first V2 to hit London was launched in September 1944. V2 attacks killed and injured thousands, but not "tens of thousands": it is said that the average death toll was about two fatalities per missile for each of the approximately 3200 launched, the vast majority aimed at Antwerp and London.
During the pub-conversation Wyatt addresses the "German" Ian Fleming as "Sir". This salutation is only used in the US for men, never in Germany.