Continuity mistake: When the Stukas are shown bombing the beach, they drop a single bomb, but from beach level, you see sticks of bombs landing.
Suggested correction: The Stukas are dropping SD-2 canister bombs, a particularly nasty anti-personnel weapon. Upon release from the aircraft the bomb divided into the bomblets you see here.
First known use was bombing of England, no evidence they were used at Dunkirk. Also, the SD-2 was smaller and produced numerous small explosions. The ones we see in Dunkirk are larger and much bigger than anything the little SD-2 could ever produce - so the original criticism sticks.
Factual error: Not until the very end of the 10-day evacuation were the French (or British for that matter) defending the very beaches themselves, and yet the movie opens with the French roadblock doing just that.
Suggested correction: While it is true the main German assault did not occur until near the end of the evacuation, what we see in the movie actually fits quite well with what really occurred. As the German Army approached, the French Army began to build defenses and roadblocks in and around Dunkirk, as well as within the city itself. The amount of gunfire we hear (just a few small arms shooting) at the beginning of the movie is indicative of a chance encounter between a German and a British patrol. While preparing for the final assault on Dunkirk, the Germans would be sending in scouting patrols to see what defenses were built and where they were located.
Firstly a scouting patrol would not open fire and give their presence away. Then the British patrol would not flee throwing away their weapons as they would know the city to be in Allied control with lots of Allied troops around. Barricades across the roads leading to the beach would obstruct Allied soldiers access to the beach, barricades would only be put up at the last moment and only to obstruct the Germans. The period is at least a week before the evacuation was completed, so the German army was miles away and there would be hundreds of thousands of Allied soldiers in and around Dunkirk. I am sorry but I had the distinct impression the Germans were only a short distance from the beach.
Having both studied and taught military history, within the military, for over 40 years, with particular emphasis on World War Two, in my expert opinion, what we see occur at the beginning of the movie is completely within the realm of factual history. Demoralized British troops have an unexpected encounter with advanced German troops entering Dunkirk ahead of the main attack to come; the Germans open fire with small arms; the demoralized British troops scatter in panic without resisting. Once it became apparent to the French they would be making a last stand defense at Dunkirk, the French did in fact begin preparing defenses. They would have been derelict not to have done so. While what we see in the skirmish at the beginning of the movie can't be pinned down to any actual engagement, it is plausible enough to be a factual representation of what occurred in and around Dunkirk at that time.
One of the things the film doesn't show is that in reality the town would have been heavily bomb damaged.
If you look very closely at the scene where Tommy's trying to load his rifle and fire in the back garden (or wherever it was) you can just about see a figure in one of the balconies in the houses in the street behind. So most likely a sniper. Also originally it was assumed the Germans were just 36 hours away when the evacuation started so it wouldn't be entirely out of the realms of possibility for a French street barricade to have been put up.
Factual error: When Commander Boulton is looking out to sea at the civilian navy he has the binoculars backwards.
Suggested correction: No, he doesn't. The objective lenses are smaller than on modern binoculars but he definitely has the binoculars the right way round. You can tell he has the binoculars the right way round because the objective lenses are on the outside of the two barrels. The eyepiece is on the inside of the barrels.
To add to the above correction, you can see WW2 binoculars at https://globalwarmuseum.com/produkt/binoculars-british-army-1943-mk-iii-x6-taylor-hobson-perfect-optics/. Commander Boulton can be seen holding them correctly at https://fyeahkennethbranagh.tumblr.com/post/168344257844/dunkirk-2017-dir-christopher-nolan.
Trivia: In reality, Adolf Hitler ordered his commanders and troops to stand down and allow Allied forces to escape at Dunkirk. The German General von Blumentritt is quoted as saying "He (Hitler) then astonished us by speaking with admiration of the British Empire, of the necessity for its existence, and of the civilisation that Britain had brought into the world...He said that all he wanted from Britain was that she should acknowledge Germany's position on the Continent." But the exact reason for the order remains unknown.
Suggested correction: Hitler's controversial 'halt' order at Dunkirk had nothing to do with chivalry. The most widely accepted reason for the order is that the Wehrmacht Panzer units had been fighting continuously for two weeks, and badly needed some rest in preparation for Fall rot, phase two of the invasion of France. Infantry and air power continued to attack the Dunkirk pocket throughout the evacuation while the armoured units rested.
