Goofs

After the fight at the beginning, young Guy wipes off the blood on his mouth. In the next scene, it is back.

Sometimes the supposed Japanese being spoken is actually Chinese.

When Gabaldon visits "Mama san" (Mother Une) at the internment camp, she says her sons are in Italy. This is prior to Gabaldon enlisting in the Marine Corps. Later, on Saipan, Gabaldon says his brothers are in the 442nd Regimental Combat Team. The 442nd landed at Anzio in May of 1944. The Marines landed on Saipan in June of 1944. Using the timeline established in the movie, there would not have been enough time for Gabaldon to enlist, go through boot camp and fight in the Battle of Saipan.

None of the howitzers recoil when fired, even though they all should. The blast and smoke are a special effect.

Each company in both the U.S. Army and the U.S. Marines has a specific number of .30-cal. machine guns. Crew-served weapons are very useful to repel a Banzai charge. For some reason though, there were no light or heavy (.50-cal) machine guns in the hands of the Americans.

The Japanese are shown using Amercian M101 howitzers.

When Guy is reading the letter from George who says he is going to be shipping out, the closeup shot of Guy is shown in slow motion as revealed by the smoke from his cigarette.

When Guy is sitting under a tree reading a V-Mail letter from Mother Une, due to the lighting one can see through the paper and it can be seen the letter is typewritten and that he is holding the letter so the type is vertical, not horizontal as to be expected as Mother Une states she is writing in English.

The tanks used by the Marines were M-48 Patton tanks, which were not produced until 1952, seven years after the war ended.

The ship shown off shore of the cliffs of Saipan is the minesweeper U.S.S. Lucid (MSO-458) which was commissioned in 1955, ten years after the end of WWII.

The Marines are shown using M67 flamethrower tanks. These were not introduced until 1955. They were probably meant to represent M4A2 Sherman tanks modified with flamethrowers.

The Japanese are shown using American M29 mortars, which were not introduced until 1952.

The Marines are using M1 carbine rifles with adjustable rear sights and bayonet lugs. These were not introduced until later in 1945.

When Guy is driven to the cliffs after reading the letter from his mother, the jeep obviously drives through the shadow of the camera platform before coming to a stop.

In all of Vic Damone's scenes as Cpl. Pete Lewis, he is seen wearing a very shiny gold bracelet, including in combat scenes. In reality, no person in combat would have been allowed to wear a shiny gold bracelet, nor would they have wanted to, out of concern for the bright glint given off which might betray their position. Damone should have been told to remove the bracelet during filming.

Guy Gabaldon's Chicano race isn't portrayed by the actors in any language dialect, people associations, mention, or even cultural appropriation. Guy as a Boy (Richard Eyer) dismisses his Chicano language and teaches English words over Spanish to Mama-san.