The ID Bands on the P-51D shown in the movie intro represent ID band used by Pacific Fighter Squadron that later on in the movie when shown in the construction of the river boat, have a red outlining which is incorrect. The red outlining was removed from all US markings after 1943.
The cargo ship displays a giant "no smoking" sign in red letters. Smoking bans on general merchant vessels became effective only in 2009. No ship in the 70's would have had such instructions prominently painted on the deck.
The film depicts an anti-Vietnam War protest in 1973 and treats President Richard Nixon's troop withdrawal announcement as a surprise. In fact, the Paris Accords had been signed in December 1972 and anti-war demonstrations petered out after Nixon accepted cease-fire terms the previous May. It was no secret to anyone in January 1973 that U.S. military involvement in Vietnam was over.
Marlow said they scavenged parts from a crashed B-29 which explain the cockpit parts on the boat but the gun turret at the stern is from a ball turret like those found on a B-17. The B-29 did not have manned gun turrets except for the tail, they were remotely controlled from within the aircraft and so would not have had any Plexiglas like the turret used on the boat. Furthermore, the B-29 was not in common use until after he was shot down.
When she is detailing her military experience Mason mentions she was "...embedded with MACV-SOG". The practice of embedding journalists with military units during wartime did not become a formal practice until the Iraq War of 2003. Prior to that many journalists during the Vietnam War, like Joe Galloway who was with the 7th Cavalry at the Ia Drang Valley, had to find their own way to the battlefield.
The US insignia on the B-29 and P-51 fuselage and wings used for the makeshift boat is outlined in red. This particular insignia was used on US aircraft only for a short time during 1943. The B-29 did not enter service until 1944, so none would have had that insignia.
Near the start of the film, Mason Weaver is examining some 35mm film, which has the words Kodak 400TX on the edge. This is new Kodak Tri-X, which wasn't available in 1973. It should have read Kodak 5063, which was the edge code for this film at the time.
Despite being an alleged former SAS member, James Conrad not only "sweeps" (passes the muzzle of his weapon across the bodies of someone he doesn't want to shoot) several people, he clearly fires directly over the head of Mason Weaver while she is standing within five feet of him. Any trained professional would avoid both of these as they could easily result in the friendly fire injury or death of a team member.
As the crew is first flying through the storm to get onto Skull Island, Packard says that Icarus's wings were "made of wax". Actually they were made of reeds and feathers with the feathers attached with wax and thus when he flew too close to the sun the wax melted and the feathers fell off.
The establishing shot of the Athena shows a CH-47 Chinook helicopter on the bow, four UH-1 Hueys amidships, and one CH-53 Sea Stallion on the stern. In the helicopter battle with Kong later, at least 10 Hueys are shown.
While Randa and Brooks are speaking with Senator Willis in the corridor outside his office, a female extra approaches them from behind and enters a room. A few seconds later, the same extra again approaches them from behind and reenters the same room.
The opening scene starts on the beach, followed by a short foot chase through the woods. Suddenly they come to the edge of a cliff that is several hundred feet above a valley below. Since they started out on the beach at sea level, and during their short run through the woods they obviously did not climb a mountain, it is impossible for them to come to a valley lower than sea level that close to shore that is not filled with water (aka a lagoon).
When she is detailing her military experience Mason mentions she was "...embedded with MACV-SOG". MACV-SOG stood for Military Assistance Command Vietnam-Special Operations/Studies and Observations Group. It was comprised of Vietnamese and American troops (Special Operations Forces like the Green Berets and SEALs) and was a joint operation with the CIA concerned with behind the lines operations, making it highly unlikely that a journalist, especially a female photojournalist, would be attached to them.
After the several helicopter crashes, the pilots are shown slogging through the jungle in regular infantry "steel pot" helmets and fatigues. Pilots don't carry "backup helmets" and they would have had only their flight helmet or maybe a rolled up cap in their flight suit. They don't bring infantry gear to change into in case they crash.
When Packard looks in his box of medals, there are a couple dog tags in there with black rubber "silencers" around their edges. These were used extensively in Vietnam to keep the two tags from rubbing together and creating noise. Yet later when the dead men's dog tags are collected, not a single one has a silencer.
The black and white photograph of the USS Lawton seen near the beginning of the film shows the name of the ship painted on the bow. American warships have their names painted on the stern, not on the side of the bow.
One pilot is shown carrying and using an AK-47. While this MAY have been acceptable on a combat mission in Vietnam, in a situation where there are no other troops similarly armed, it would be unacceptable and rather foolish. The shooter would be unable to either receive additional ammunition from a teammate in a crisis; nor would they be able to scrounge ammunition if they ran short.
One of the helicopters is called a "Sea Stallion" which is the US Navy/USMC designation of the H-53 helicopter platform. The Army's version of this aircraft was nicknamed the "Jolly Green Giant". An Army officer in an aviation unit would NOT have made this mistake.
When Marlow describes the building of the boat, he says parts were taken from his P-51, Gunpei's Japanese Zero, and a B-29 they found on the beach. But the twin machine guns on the bow were inside a Sperry ball turret, which was used on B-17s and B-24s but NOT B-29s. Also, the guns in a ball turret had special firing mechanisms for the turret operator and were not fired with traditional grip triggers as shown in the movie.
The deckhands launching the helicopters off the ship are wearing red jerseys and "cranials" which on board ship indicates they work either as firefighters or ordnancemen. The proper jersey color for launching aircraft would be yellow for an aircraft handler. The argument may be made that the ship was civilian not navy, but then none of the deck crew should have had on navy aircraft department gear at all.
Randa states that his ship, the USS Lawton, was reported to the public as being sunk in action. The photograph that he produces of the ship, however, shows it to be a battleship. In World War II, the US Navy never reported a battleship lost after the one sunk during the Pearl Harbor raid.
The photograph of the 'USS Lawton' shows it to be a South Dakota-class battleship. However, it was the US Navy's official practice to name battleships after states, so it is highly unlikely that there would be a battleship named after a person. A better choice of warship type would have been a destroyer, which were, and still are, usually named after notable persons in the Navy or Marine Corps.
Mason was shown loading Kodak Plus-X film into her camera, which is, or was, a mid speed black and white film, OK for daytime shooting, but not for low light shots as she is seen taking later, at least not without camera shake and blurring or unless you use flash equipment. Also, as it is black and white, it isn't what you would use to capture the colors of the Southern Lights and a timed exposure would just be a bunch of gray blur. Many photographers carry more than one type of film and there may have been an off camera switch of film types.
Japanese pilot Gunpei Ikari attempts to use a German Mauser C96 pistol at the beginning of the film. Although Japanese forces would not have been able to obtain additional munitions at the end of WWII due to financial issues, the munitions they already had would still be in circulation.
Several times throughout the film it sounds as if Packard is referring to Major Chapman as "Captain," which is a lesser rank. However, this is due to Samuel L. Jackson's accent/inflection in which he frequently pronounces the name Chapman as "Chap-um". This can be heard by listening carefully to the dialogue.
Japanese pilot Gunpei Ikari was shown holding a German Mauser C96 pistol at the beginning of the film, even though Imperial Japanese Navy pilots were not issued with this type of gun. It would not, however, be surprising if the pistol were to be a private weapon that Ikari bought for himself. It was not uncommon for officers, including pilots, to carry their own weapons in wartime.
Although Northern Lights aren't visible in the southern hemisphere, they could have been seeing the Southern Lights. However, it is more likely that the lights and Skull Island's unique storm system are due to the 'hollow earth' characteristics which are never fully explained.
Weaver said her flash broke, thus was not able to take long exposure shots of the aurora. Any competent photographer would know that long exposures do not require flash. However, she says her flashlight is broken not her flash, she just needed some light to see her camera clearly so she could set it up right, hence why she uses the lighter to do so instead.
Flipped shot: When Mason fires the flare gun at the skull crusher, she is shooting left handed. This is shown by the strap on her bag crossing left to right instead of right to left as seen in shots before and after this.
Flipped shot. When Mason is taking photos of the local tribe, her film advance lever moves from the normal right-hand side of the camera to the left hand side of the camera. The viewfinder also swaps sides.
Jack, after filling his canteen, ends up hiding behind a rock as Kong approaches in the water, tending his wounds. The scene continues with Kong fighting the largest squid in Earth's history, no more than about 500 feet away from shore. Yet, despite all the violent activity and water splashing, no waves reach shore nor Jack, for that matter.
When Kong saves Weaver from drowning, she is lying in his hand upside down when she should have been upright. This is shown when Kong reaches into the river and grabs her. After Kong saves her from the alpha Skullcrawler, Weaver's position in Kong's hand changes as he puts her down. She goes from being inverted to being sideways then returns to her original position.
Admittedly this is about an imaginary species but it defies physics that the flying dinosaur/bird creature could have carried off Nieves. The maximum carry load for most flying predators is around half their own body weight although a bald eagle was observed carrying a deer fawn that was near its own weight. Nieves is 5' 8" and probably weighs around 165 lbs. The movie creature didn't look much bigger than a Stellar's sea eagle which is one of the largest raptors that carries its prey whole and whose body weight range maxes out around 20 lbs.
When Cole plans to sacrifice himself with the grenades he pulls the pins and releases the spoons. This sets the 5 second timed fuse, but there were more than 5 seconds from arming to detonation. The resulting explosion was also way too large for just two grenades, and though he was carrying several others he didn't arm them as well.
When the soldier is filling up his canteen, he sees Kong walking right in front of him and being attacked by a giant squid. If he was filling his canteen, it couldn't have been salt water, and squids don't live in fresh water.