When Danny (Tab Hunter) are in Mrs. Yarborough's (Dorothy Malone) apartment she is obviously wearing a "style of the 40's" bra, but when she goes into her room to change to go swimming and takes off her red sweater there is no sign of any bra, or any other undergarment.
When the unit arrives at Guadalcanal, as they march off some of the men in the first group have wet trousers from the landing on the beach, but the men in the second group have completely dry trousers.
While Danny talks to Elaine at her apartment his shirt is alternately buttoned/unbuttoned between shots.
Several scenes show African Americans in a predominantly white unit. The armed forces were racially segregated in WWII.
A lone Jap fighter drops 2 bombs from under the planes wings but there are 9 explosions,
When the unit first comes under enemy air attack, the path of explosions on the ground take a sharp turn from the left to follow the men along the road. It is physically impossible for any plane to turn sharply enough to leave that sharp a pattern on the ground
Andy chops down a tree about 1:20 into the film with an axe. When the tree falls you can clearly see from the stump the tree was sawed, not chopped.
When Colonel Huxley goes to ask General Snipe for a beach head he is not wearing a tie clip. He should be wearing one.
When Andy Hookins chops down the tree in front of Pat's house, he visibly "chops" it with an axe, but when the tree falls the camera pulls back to show the tree falling from a perfectly smooth stump, obviously cut with a chainsaw.
During the battle scenes on Saipan, the Japanese are shown using American-made M4-A3 Sherman tanks, albeit with Japanese markings.
The Japanese are seen using several Amercian M116 howitzer artillery pieces, and at least one M101 howitzer as well.
Although the story takes place in 1942, all of the women's clothing and hairstyles, particularly those of Nancy Olson, Dorothy Malone and Mona Freeman, are strictly 1954; the sole exception is Anne Francis, whose appearance does actually imply the correct era at least to some extent.
There are several shots at MCRD (San Diego), and of the battalion marching with African-American Marines in the ranks. In 1942 and 1943, integrated units did not exist. It wasn't until 1948 that President Truman signed an Executive Order to investigate full integration of the armed forces.
When the marines arrive in New Zealand they are seen marching away from the transports that brought them. The ship to the right is marked APA-208 which would make her the U.S.S. Talladega. The Talladega wasn't commissioned until 31 October 1944, two years after Guadalcanal.
At the company dance (during WW2, c. 1943), the song "Put 'Em in a Box, Tie 'Em with a Ribbon, and Throw 'Em in the Deep Blue Sea" is played by the band. This song wasn't published until 1947.
Danny and Kathy make a surprise announcement to their parents in Baltimore that they eloped overnight and were "married in Elkton." While Elkton, Maryland was widely known throughout the Northeast as a spot for quick weddings during the 1920s and 1930s, after 1938 state law required a 48-hr waiting period between issuance of a marriage license and a wedding. Thus, during WWII they could not have eloped without advance planning.
During the Boot Camp graduation parade, the music starts playing before the band has raised their instruments.
Marines East of the Mississippi go to Parris Island for boot camp, not San Diego.
A quick correction. Not all USMC recruits east of the Mississippi go to MCRD-Parris Island. The vast majority of them do but there are some east of the Mississippi who are sent to MCRD-San Diego; those from Wisconsin and northern Illinois for example. There are other areas just east of the Mississippi as well that will see recruits go to MCRD-San Diego, some of that has to do with staffing levels and recruit numbers at each of the Recruit Depots.
Mrs. Pat Rogers speaks with an American accent even though she's from New Zealand.