Baker is sent to sick bay with infected right foot but when Nicholson asks for volunteers for the bridge Baker then has an infected right arm instead.
When Colonel Nicholson is examining the wire sticking out of the river, the current switches direction.
When the bridge is blown up, the pier on the left explodes first, and you can see smaller charges detonate from under the deck where the commandos never set their charges. Then 7 seconds later, the pier on the right explodes, which would not be possible with only one push of the plunger.
When Col. Saito leaves Col. Nicholson and the other officers standing in the sun, their shadows lengthen during the day. The scene then cuts to a view from inside the 'hospital' and the shadows of the officers are noticeably shorter.
When Major Warden is waiting with the mortar gun, the Thai woman helping him loads the gun twice, but it only fired once.
Japan was not a signatory of the Geneva Conventions until 1953, therefore there was no expectation by Allied prisoners of being treated in accordance with them. In fact, the Japanese mistreatment of prisoners of war led to the review and update of the conventions in 1949.
The movie credits have only one 'n' in Alec Guinness' name (this has been corrected in the "restored" version).
Nicholson and his engineers convince Saito to move the bridge 400 yards further down the river to take advantage of the narrower gap and solid river bottom. But no mention is ever made of how they're going to connect the new bridge to the railroad which was heading to the old bridge site.
Shears (William Holden) said he stole and uniform and impersonated an officer because he believed the Japanese would treat an officer better. In fact, the Japanese treated captured officers far worse the enlisted men. In German POW camps they were both officers and enlisted men were treated the same.
When Shears escapes from the camp the Japanese soldiers in pursuit are carrying British Army issue Lee Enfield SMLE MkIII rifles.
At the start of the movie, while the officer's and men are marching, they whistle. Unfortunately, while their whistling is meant to help keep them all in step, the music does not match their marching steps. In fact, had they been marching in step, their left foot would have been on the first and third beats of the song. This is done intentionally to show that at the beginning, the soldiers are disorganised and unable to whistle and march to the beat. When the theme plays again at the end, after the bridge has been built, they all whistle and march perfectly, showing their progress.
Many Japanese POW camp commandants equipped their guards with British equipment because of an abundance of British ordnance after the fall of Singapore in 1942 and the difficulties in equipping main line troops with new equipment so far from Japan, much less camp guards who would not be near the fighting and would not require constant resupply. The warring nations equipped prison camp guards with second hand equipment. As such, it is not a goof that the Japanese soldiers do not have Japanese weapons.
It wouldn't have been necessary for Joyce, the Canadian, to go to the UK to enlist to fight against the Japanese, as he says when being interviewed to join the commando group going back to the Kwai. Canada joined the war only ten days after war was declared by the British, and Joyce could easily have enlisted at home in Montreal.
While the prisoners are all supposed to be sick and/or mistreated, in fact all look reasonably healthy and even tanned, and none in any kind of starved or emaciated state. In reality, as numerous photographs of actual prisoners of the Japanese show, all prisoners were uniformly emaciated, having lost an enormous amount of weight, starved, and with skeletal frames - conditions noticeably absent from any of the prisoners in the film. However, Saito was based on one of the more humane commandants who was acquitted of war crimes after war's end.
Major Shears and two others try to escape. It is indicated that two are killed and one drowns (supposedly Shears) but the Japanese carry three bodies back to camp to be buried. The third body is the Japanese guard Shears killed before he vanished into the bushes, and was chased into the river.
The first time that Warden is seen to be looking at the bridge site through binoculars he is clearly actually only looking at the rock ledge, on which he is lying, a few inches in front of him.
In the finale the bridge is blown up and the train crashes into the river, but a moment later in a scene showing the destroyed bridge, there is no train.
Even though the setting of this movie is primarily jungle/rainforest, you never see a single insect or anyone swatting or shooing one.
After Lt. Joyce has decoded the message they got from the radio he is reading it to them while it's supposedly still raining but the raindrops are only splashing on the close side of the river and not on the far side closer to the opposite bank.
Many of the extras are clearly Sri Lankan/Ceylonese, not Thai.
When Nicholson and Col. Saito discover the det wire in the river bed Nicholson pulls the wire out of the mud and asks Col. Saito for a knife and Saito pats his pockets, finds nothing, conveniently forgetting he has a samurai sword on his belt.
When Shears is jumped when he first reports to the British commando school it's obvious that the knife blade is rubber when it constantly wobbles.
When Shears is jumped when he first reports to the British commando school it's obvious that the knife blade is rubber when it constantly wobbles. However, one would expect a knife with a rubber blade to be used in this instance since this is a training session, not actual combat.
(at around 37 minutes) The calendar on Colonel Saito's office is correct for February 1943. However the pinup on that calendar was not drawn until 1955 by Gil Elvgren entitled "Waiting for You".
When a Burmese woman spreads masking paint on Major Shears' legs, before they are to set charges onto the bridge, it's clear that William Holden is wearing 50's style loafers that not only do not fit the time, but don't fit the situation at all.
The movie is set in 1943, yet a 1946 Chrysler was shown as a military staff car.
The roofs of some of the buildings in the hospital scene have television aerials on them. Since the film was set during WWII, the only countries which had television in any significant capacity were either in North America or Europe. There shouldn't have been any television aerials as was no need for them.
The Japanese soldiers are never seen using anything except British weapons throughout the movie. The Japanese soldier on the train in the opening sequence has a variant of the Vickers machine gun, as do the soldiers in the back of the truck. All infantry are carrying either Lee Enfield (Mk III or IV) rifles or Thompson sub machine guns. There is no Japanese weapon at all in the film except for the officer's katana, or personal sword.
After the three prisoners try to escape, the next day Major Clipton is talking to Saito in his hut about the men sabotaging the bridge. Saito says " I could have them all shot" to which Clipton replies "Then who would build your bridge?" Immediately after that if you look out the window, you can see a crew member running by in a white shirt and grey pants.
During the first two formations in front of Colonel Saito's office, the sun is behind the men, yet some shadows in the foreground caused by the movie lights behind or to the sides of the cameras are visible.
In the very last shot of Major Clipton, waves in the water caused by the helicopter pulling up to film the scene are visible.
In the opening scene, the railway is 5'6" (1.676 m) broad gauge, as used in Ceylon (Sri Lanka), the filming location; but when tracks are shown on the finished bridge, they're much narrower, about 2' (60 cm). The actual line would have been 1 meter gauge, as it connected existing Thai and Burmese meter-gauge routes.
When Shears is escaping from the camp, he is shown traipsing through an arid, desert-like landscape. His empty canteen is dragging behind him and he appears to be thoroughly parched. He collapses on the edge of a Thai village. When he departs the village after having recovered his health, the village is shown to be on a river's edge and surrounded on all other sides by lush jungle. No arid landscape is in the vicinity.
The hospital entrance says: "Mount Lavinia Hospital Ceylon." The movie is set in Thailand/Burma but filmed in Sri Lanka (Ceylon).
Saito tells Nicholson that he spent three years studying at London Polytechnic, which would presumably mean he would learn the British pronunciation of English words. But while he does refer to his own officer, Lt. Miura, as "Lef-tenant", he also complains that the bridge will not be completed on "schedule", using the American pronunciation, with an "sk" sound, instead of the British "sh" sound his education and experience in England should have led him to use.
At the end sequence with Major Clipton walking up on the damage and his fallen comrades his reaction is not in keeping with being a doctor as he simply says: "Madness!". A doctor would have been checking to see if his commanding officer and his fellow soldiers were still alive.
At the first officers' meeting, Col Nicholson says Jennings' name right, then he says it as Jenning.