Early in the movie, we see Jim Apperson announce that he has enlisted. His father, who had been sternly lecturing him moments before, comes up and congratulates him. Suddenly, the father now has a lit cigar in his mouth, with a long ash, indicating he's been smoking it for at least a while. But all the time prior, we saw no sign that the father had a lit cigar anywhere on him or near him.
NOTE: At the time it was customary for men (especially older men) to celebrate something by having a cigar. Mr. Apperson's sudden appearance with a stogie illustrates how proud he is of his son, as opposed to Jim's mother, who is heartbroken in the same shot. For director King Vidor, making this symbolic point was evidently more important than showing how the cigar got there.
NOTE: At the time it was customary for men (especially older men) to celebrate something by having a cigar. Mr. Apperson's sudden appearance with a stogie illustrates how proud he is of his son, as opposed to Jim's mother, who is heartbroken in the same shot. For director King Vidor, making this symbolic point was evidently more important than showing how the cigar got there.
This is the first American war movie where the soldiers are seen pulling grenade pins out with their teeth, which is impossible.
The soldiers march past eucalyptus trees during the Belleau Wood sequence. Native to Australia, eucalyptus trees are not found in that region of France. They can, however, be found in Griffith Park, Los Angeles, where the sequence was shot.
While billeted in Champillon, Jim thinks up and builds a functioning shower bath using a barrel. Nothing shown of his idle rich boy background suggests he would have the handyman skills to do this. It was simply a plot device that allowed Jim and Melisande to "meet cute". Twice.
In the hospital scene after the battle, a soldier apparently suffering from PTSD screams and thrashes about. His body is tied down to the bed but his hands are left free, which in reality would defeat the purpose of the restraints.
At around 69 minutes when Jim is leaving on the truck he throws a shoe to Melisande. There is a shot when she is holding the shoe with a truck passing behind her. There is a clear shadow of Meliande on the side of the truck that was obviously from a studio light.
When Jim is getting dressed in the hayloft for his date, Slim jokingly refers to him as "Mr. Hemingway". When the film was being made in 1924-25 Ernest Hemingway was becoming famous, but in the movie's time frame of 1917, he was still unknown.
In the recruitment parade scene, several women are wearing drop-waisted dresses with hems that end well above the ankle. This is appropriate for the year of production, 1925, but quite anachronistic for the time in which the scene is ostensibly set, 1917.
The three future recruits live in New York City (one works construction on a skyscraper, another works a bar in the Bowery), but during the recruitment parade, there are shots of wide avenues lined with low buildings and palm trees - clearly shots of 1920s Los Angeles.