The two MPs who appear early on the film are named Mangold and Pennycate. This is an homage to Tom Mangold and John Pennycate, authors of the book THE TUNNELS OF CU CHI, which was an instrumental reference source for the screenplay.

All the signs in the so-called "Ho Chi Minh" city are in Thai, which doesn't look even remotely like Vietnamese. Vietnamese language is written in the Western alphabet, with accent symbols over some letters. Thai has its own alphabet, quite indecipherable to Westerners.

The movie on Beckett's motel TV is The Bridge on the River Kwai (1957).

In real life, actor John Doman (who plays Paul Finnegan, Beckett's comrade turned adversary) was a lieutenant in the United States Marine Corps and Vietnam veteran, and served under the 3rd Marine Division.

M50 Sniper Rifle Remington 700 Rifle in the Vietnam flashback, a young Thomas Beckett is seen using a Remington Model 700 sniper rifle. Vietnamese police detective Quan (Byron Mann) later gives Beckett another Remington to use. When Quan asks what Beckett thinks of the rifle, he says that it is "the best damn sniper rifle ever made".

Continuity

While Beckett is watching "The Bridge on the River Kwai" in his hotel room, the scene of James Donald saying "Madness!" precedes the blowing up of the bridge. In the actual film it followed it.

When Beckett and Detective Quan are in the tunnels Beckett is carrying a sidearm in his left hand and rifle with his right hand with the index finger "missing", but in another shot it is carrying the rifle in his left hand and the handgun in his right showing the index finger on the trigger.

Beckett kills Finnegan by shooting a man in the hand that was holding a gun to Quan's head, causing the hand to rotate and the trigger finger to spasm and shoot Finnegan. The man whose hand was shot should have been screaming and holding his hand, but in the entire next scene there is no sign of him.

When Quan enters People's Unification Building he has patch on his left cheek. After meeting Beckett the patch disappears.

When Beckett is sitting in the motel room watching the old war movie, he is drinking Jack Daniels from a glass. The glass changes hands between shots.



Factual errors

On the roof, he shoots another sniper with a handgun. The shot is next to impossible to take with a handgun because of the distance.

Apart from the driver being on the right of the car instead of the left as it is in Vietnam, the streets are far too empty. In Vietnam the streets are clogged with motorbikes spreading onto the footpath. You will never get empty streets as shown in the movie. Plus the signs are all in Thai not Vietnamese.

When Beckett is being recruited, his Combat Action Ribbon is backwards.

When he is being recruited, Beckett is wearing the Marine Corp, charlie uniform. This is worn with a white T shirt. Not the green skivvy shirt worn by Beckett.



Revealing mistakes

Beckett's "missing" index finger is simply folded back into his hand and is visible in some scenes.



Errors in geography

In several occasions in jungle locations, the call of a Screaming Piha can be heard. The Screaming Piha is a bird of the Americas and is not to be found in Viet Nam.

After Thomas Beckett has arrived with a Thai Airways plane in Ho Chi Min City he drives with a taxi into town. There are shop signs and ads visible, however in Thai language and not in Vietnamese. (The film was shot in Chiang Mai, Thailand.)

In the driving scenes, the car is on the left and the driver is on the right. If this was in Vietnam this would be reversed.