In the dance sequence with Eugene and Daisy during "How High the Moon" as they slowly dance in circles, you can see the shadow of the entire crew, camera and boom against the back wall with each rotation!
At the end of the movie, as the voice over nears its finish, we see a shot of the train traveling across a very long bridge over a river. The shot, unfortunately, also reveals modern track switching and communication boxes, not found in 1945, spaced at regular intervals along the bridges length.
At the end of the film, as Eugene is narrating over the shot on the train, he says that the atomic bomb was dropped on Hiroshima "and six days later, the war was over." Japan surrendered 9 days after Hiroshima, which was bombed on August 6. The surrender came 6 days after the bombing of Nagasaki, which was bombed on August 9.
When Sgt. Toomey first greets the men, he quietly calls for "attention". When the troops don't react to his liking, he repeats himself. Though you hear him shout "ten-hut!", he is clearly mouthing the word "attention" again.
When Sgt. Toomey is first reviewing his platoon, he says that they will either be sent to the Pacific or northern Sicily. However, the film takes place in 1945, and the Sicilian campaign was long over, Sicily having been invaded and secured in late summer of 1943. By 1945, virtually all fighting was taking place in Germany itself.
When the platoon first meets Sgt. Toomey they are standing in an empty field across the road from the front of their barracks. Later, when they enter their barracks there is another building across the road.
During the game in the barracks, Wykowski says that he wants to "make it" with the Queen of England. Selridge says "that's like making it with your own grandmother". First, there was no "Queen" in 1945. In 1945 future Queen Mother was the "Queen Consort", wife of King George VI and only 45 years old. She was not elderly as she was when this movie was made and certainly not an age you would consider her a "grandmother".
This movie starts out in July 1945, as established by Sgt. Toomey during the first meal after they arrive in Biloxi. Because of this, several events and statements are factually incorrect or out of sequence; 1. Sgt. Toomey says that they could be sent to the Pacific or Sicily, but Sicily had been liberated two years earlier. 2. The "Movietone News" at the end of the movie they are watching shows the headline "Allies Hurl Nazis Back In Italy", but the the Italian campaign had ended May 2, 1945. 3. Sgt. Toomey tells Epstein that he will be "the first man to reach Berlin", but the war in Europe ended on May 8, 1945 and Berlin had already been occupied. 4. As he's riding on the train at the end of the film and narrating, Jerome states that they were headed for the battle of the Pacific but suddenly they dropped "the bomb" on Hiroshima, and 6 days later the war was over. They would not have been finished with their 6 weeks of Basic Training when the fist atomic bomb was dropped on Hiroshima on August 9th, 1945.
The movie is set in the Spring/Summer of 1945. Sergeant Toomey, addressing the men when he first meets them, states that they will likely be sent to "some island in the Pacific, or Northern Sicily." Sicily was in allied hands two years before the film is said to take place.
During the scene in which Wykowski discovers that his wallet has been emptied, Hennesey tells Wykowski that he's Black Irish. Black Irish refers to those of Irish descent who have dark brown/black hair and brown eyes, as opposed to the fair hair and blue eyes that are more characteristic of the Irish. The actor who portrays Hennesey has red hair and blue eyes.
Soldier named: Peak, David P, was referred to as "Sweeney" (one of the soldiers ordered to give 100 push-ups, by Sergeant Toomey) after the scene where Wykowski and Epstein have their confrontation, following the game where the main characters tell their fantasies for money.
Near the end of the film, Christopher Walken is standing in the rain. One moment his uniform has combat ribbons, a second later the ribbons are gone and then they reappear and disappear throughout the scene.
The scene where the troops are talking about what they would do with their last week on Earth. Wykowski makes reference to "making it" with the Queen of England. Because George VI was on the throne, his wife, later known as the Queen Mother, was Queen of England.