When Tom and Betsy fight on the lawn it's clearly night. Tom goes in the house, lights a cigarette, and runs outside to see Betsy leaving in the car. It's now clearly day.
Tom and his unit are transferred from Italy in July 1945 (according to what he tells Betty later) to the Pacific. They then participate in a major airborne amphibious assault. In reality, there were no major actions in the Pacific at that time. The last one, the Battle of Okinawa, ended in June; it had no airborne element.
Tom Rath was in Italy in June and July 1945 having the affair; however, the war in Europe was over in May; Rome was liberated in June 1944.
Tom Rath and his paratroopers belong to the 509th Parachute Infantry Battalion, which actually saw combat in Italy during World War II. In reality (unlike the film), the 509th did not get sent to the Pacific Theater to fight the Japanese (or make a combat jump there) after the battalion's tour in Italy was over.
At the end of the movie, Tom shifts the 1950 Ford manual transmission into reverse in order to pull forward.
Tom claims the affair was in June 1945, and the war in Europe was over by that time. Tom also claims he was emotionally mixed up by having killed 17 men and was not sure if he would die in the next action; so that excuse is a year late.
It is believed by some that Tom shifting his car into reverse then driving away forward at the end of the film is a goof. However, the car is a manual transmission Ford with a column-shifted 3 speed manual transmission with an unsynchronized first gear. A quirk of that style transmission is that at a standing stop, getting the transmission into 1st gear when the engine is running is easiest if the operator first abruptly lifts the shift lever from neutral to place the transmission into second gear, then back down into first. This prevents clash (grinding) of the unsynchronized first gear. Drivers of the era, including Tom Rath, would have been well familiar with this technique.
When Mr. Hopkins asks Tom to have a drink with him, Tom offers to fix them. Mr. Hopkins says he wants Scotch on the rocks. Tom then pours two drinks neat.
Tom clearly puts two ice cubes into the first glass.
As Betsy is driving Tom home from the train at the beginning of the film, the car doesn't correctly respond to how she moves the steering wheel.
Near the end of the movie, when Betsy is at the police station, Tom asks her over the phone if there are any charges against her. The policeman answers, "Just bring the license" before Betsy can ask him if there are any charges.
As Hopkins (Fredrick March) arrives at his wife's home, in the long shot at the beginning of the scene, the afternoon sun is clearly shining upon the front door. When cutting to a semi-closeup as he walks up to the front door, the entrance to the house appears to be in the dark of evening.
During the combat parachute jump, the paratroopers jump from C-119 aircraft, a type that was not available during World War II.
The opening shot of a New Haven Railroad train supposedly shows Tom's train home, leaving New York in the evening. However, the sunlight should be on its port side (as it is in the following interior shot).
Betsy must have obtained the car keys during her argument with Tom before she ran out of the house, yet it's never explained how.
When Betsy picks up Tom at the beginning of the movie, she left her 3 young children alone at home, and one had chicken pox.