The first Japanese air attack, the aircraft change many times, from fixed-landing gear to biplanes then to high-level bombers.
In a shot of the Japanese ships just before the Marines open fire, a patrol boat can be seen already on fire.
When Maj Caton (Brian Donlevy) is talking to Lt Cameron (Macdonald Carey) who is forging a part for his airplane, the tail of the airplane behind him his not of a F-4F Grumman Wildcat, the only plane assigned to Wake Island. It appears to be that of a North American BT-9 training plane. The F-4F tail is squared off at the top of the fin, while the tail of the plane in the scene comes to a point.
During one of the scenes showing the bombardment of the island, the Marine CO has ordered the observation tower evacuated. Later scenes show two men still in the tower when it is destroyed.
During a Japanese bombardment on the 14th day there's a shot looking at the island and all the marine's tents are intact.
No Catalina, or any form of help, arrived for the Wake Island garrison during the siege.
The garrison Wildcats did not sink a cruiser. They sank the destroyer Kisaragi.
The film says the garrison was only Marines. In truth, the garrison was led by Navy Commander Winfield S. Cunningham. There was a 68-man Navy and a 5-man Army signal detachments. As well as around 1,200 civilians. Most of whom fought the Japanese.
At the end, the Japanese are using German 'potato masher' hand grenades. They did not use such grenades. Their grenades didn't use a long wood handles. Pulling the pin exposed the hammer that the soldier had to smack on a hard surface, like their helmet, in order to arm it.
During the aerial battle at around 38 minutes one of the island defenders is shown shooting down a biplane. Biplanes would have been phased out as tactical weapons long before the war began.
The scene showing a Japanese aircraft doing a recon of the island, has sharply tapered wing tips and fixed landing gear. However, the shadow of the aircraft has rounded wing tips.
At the beginning when the PBY is taxing to the pier, there are mountains in the background. No mountains exist near Wake. Filming took place in Southern California at the Salton Sea.
Pilot, Lt. Cameron asks his Wildcat be drained of all but fifteen gallons of fuel. That way his aircraft could carry the extra bombs. With fifteen gallons of fuel, he wouldn't even make it to his target.