Corrected entry: During the Dunkirk beach scene the soldiers are heard singing "(There'll Be Bluebirds Over) The White Cliffs of Dover". The evacuation at Dunkirk took place in May 1940, but the song was not written until 1941.
Corrected entry: In the approach to Dunkirk, Robbie is carrying a pistol, complete with webbing holster. He has no rifle and is carrying a bayonet on his haversack, presumably not having the usual belt frog to carry it more easily. As a Private (this is emphasized in the dialogue) in an infantry regiment, he'd have carried a rifle and not a pistol. Although he might have acquired the pistol during the retreat, he's less likely to have changed his webbing order to match. This may be a deliberate directorial choice. The dialogue emphasizes his natural "officer qualities", and that his prison record has prevented him from becoming one. The wearing of officer's equipment, even if historically inappropriate, also reinforces this and distinguishes him from his comrades.
Correction: It is quite possible that Robbie would be carrying a pistol with appropriate webbing, even though only a private. One commander of a BEF battalion complained that one third of his soldiers were "only armed with pistols" in 1940. Usually this happened when the unit was a motorcycle or armoured unit being used as infantry. Individual privates, eg drivers or despatch riders, might also be equipped with pistols.
Corrected entry: The BEF was a professional army and was not staffed with conscripted prisoners.
Correction: Robbie wasn't conscripted [forced into service], he was offered parole in exchange for joining the army. He was a free man once he entered the army.
Corrected entry: In the fake newsreel of the chocolate factory owned by Paul Marshall, the British ruler at the time (June, 1940) is shown and stated to be Queen Elizabeth. In reality, Queen Elizabeth II did not ascend the throne until 1952 upon the death of her father, King George VI. (01:35:00)
Corrected entry: When Briony enters the kitchen to say she has finished her play, the cook tells her to go away as they have a dinner for 10 to prepare. The Mother, Cecelia, the brother, his friend, Briony, Lola and the twins make only eight. Robbie is not invited till after this and then it still makes only 9 for dinner.
Correction: Any number of reasons accounts for this: Rounding up the number in conversation, exagerrating her workload, expected guests that never arrived, normal 'extra' food in case of surprise/last minute guests, and so on. At worst, a character mistake.
Corrected entry: Briony is played by 3 actresses, from a 13 year old girl to an elderly Vanessa Redgrave. I suppose that, in order to identify each actress who played the role, a mole was placed on Briony's face. The 13 year old Briony has the mole on her right cheek. The young nurse Briony has the mole on her right cheek. The first scene we see the Vanessa Redgrave Briony, the mole is properly on her right cheek. Then, suddenly, in a close up, the mole appears on Vanessa's left cheek. In the next scene, it's back on her right cheek.
Correction: The shot with it on the "wrong" cheek is her reflection in the make-up room mirror.
Correction: The song the soldiers are singing is "Dear Lord and Father of Mankind." It's a hymn with words taken from a longer poem written in 1884.