The car Eugene Sledge is picked up with on arrival back home to Mobile has a different license plate number in the next scene arriving at his home.
When John Basilone's wife Lena, who was also a Marine, visits John's family at the end of the war, there are no award ribbons on her jacket. As a minimum, she would have earned the American Campaign Medal for her service in the United States.
At the Sledge family dinner when a soldier shows a nazi flag he says that he got it from Prague. The American army was never in Prague - it was liberated by the Red army.
When Burgin is arriving home in Jewett, TX. He alights from a Louisville & Nashville Railroad train at an L&N depot. L & N never went west of New Orleans, LA.
When Bob Leicke was "re-interviewing" for his old job at the Bergen Evening Record, he said he wanted to cover a football game between Don Bosco Prep and Bergen Catholic. Bergen Catholic High School opened on September 11, 1955 - 10 years after the surrender of the Japanese in Tokyo Bay. A better choice for script choice would have been Bob's own Parish High School, Saint Mary High School was founded in 1929 or St. Cecilia High School (Which has closed in 1986) where THE Vince Lombardi was the Head coach at St. Cecilia High School in Englewood, NJ (1942-47).
When 'Snafu' is on the train, he is wearing a green rope, I believe the fourragère was awarded to 5th and 6th Marines in 1918 for participation in World War I, from Belleau Wood to Château-Thierry. Since then Marines assigned to the two regiments have worn the green braided rope over their shoulder in their service and dress blue uniforms, not the 1st Marines.
After returning home, Eugene Sledge and his brother, an Army tank officer, are having a conversation outside their home. The brother wears the Distinguished Unit Citation ribbon, but it is incorrectly placed. He wears it along with his other ribbons over his left coat pocket, but it should be pinned over his right pocket.
Eugene Sledge gets off the train at his home town still wearing his uniform but without the green braided cord (Fourragere) that is worn by the 5th and 6th Marine as the French awarded them for their fighting gallantry in WWI.
In the previous scenes on the train the same can be seen correctly worn on the left shoulder by both Snafu and Burgin.