At the 38 minute mark, when the Halifax bombers are seen towing the gliders, the glider on the left has black and white strips on the wings and tail. These markings were only used starting on June 6th, 1944 for Naval gun crews to distinguish between Allied and Luftwaffe aircraft during the Normandy landings.
The British glider planes have the white "invasion stripes" too early in February 1943. Actually they were first used during the invasion of Normandy in 1944.
At the crash site of the glider on of the wounded soldiers crack a cyanide potassium capsule and obviously die in very few seconds.
However the cyanide potassium will only after few minutes in the stomach be transformed into hydrogen cyanide acid which is the deadly poison that paralyzes the breathing ability.
Gliders are shown being towed to the landing site for the assault on the heavy water plant "Operation Grouse" which took place in 1942. However, the gliders have the black-and-white D-Day invasion stripes on them, which didn't happen until 1944.