Continuity mistake: In the scene when Dorothy hands her bible to Desmond on the bus, he is seated on the passenger side. However, after the bus departs, he is suddenly seated on the opposite side. (00:26:45)
Continuity mistake: When the Privates are having their furloughs authorised, Colonel Sangston walks in with Corporal Cannon. Only those two men walk in. Corporal Cannon moves from the doorway to give Desmond Doss his rifle leaving no-one by the doorway. After Desmond refuses to touch the rifle, the Colonel shouts at Desmond. Out of nowhere Captain Glover mysteriously appears in the doorway. (00:48:40 - 00:50:10)
Revealing mistake: When Desmond Doss slides down into the tunnel to hide from the Japanese there are rats crawling over the body of a "dead" Japanese soldier but his breathing is visible at his stomach/belt. (02:15:00)
Factual error: Throughout the battle scenes on the ridge, the machine gunners can be seen picking up the guns to fire on the move. While not impossible, not as painless as it is made to appear. The M1919 .30 caliber air cooled machine gun was light enough to carry. But for the gunner to hold an already hot barrel and continue firing would have been extremely painful without the issued heat retardant mitten or the barrel "hoop" w/ wooden handle. These fixes allowed the gun to be fired on the move and saved many from having their palms burned and scarred for life.
Suggested correction: They have barrel shrouds which dissipate the heat and allow a grip...they are not in contact with the barrel.
Factual error: When Desmond's father is in his WW1 uniform, to the far right he is wearing a French Croix de Guerre (Cross of War) - the medals themselves are identical however, this decoration incorrectly hangs from a WW2 type ribbon.
Revealing mistake: When the stretcher is being lowered down on the line, the high tension steel wires can be seen under the hessian rope.
Suggested correction: I don't see this as an error, because just before they lower him down, it is obvious that they have rigged a tripod and cable at a much lesser angle than straight down the face of the cliff. Once the cleanup phase started, additions like this would have been normal to remove the dead and wounded.
I am 100% certain this is an error.
The stretcher is seen lowered down hung from ropes tied at each corner, which would have really happened. Obviously this wouldn't meet safety requirements for filming, so they've "hidden" steel cables in the rope. The error is that the cables and the screw-in anchors in the stretcher are visible. Also the rope on some of the corners is visibly slack as a result.
This doesn't refer to the tripod and cable rig. Just as the stretcher starts moving, the camera shows it moving off to the left with the other soldiers watching on. One of the soldiers is holding one of the ropes that attach to the stretcher. When he lets go, it reveals that the rope is frayed, revealing the steel wire that is threaded through the rope. It's the wire that's attached to the stretcher, not the rope.
Factual error: Once the men first climb up to "Hacksaw Ridge," the camera pans over numerous corpses. One of them has an M1 Helmet lying on its top to where the liner is seen. The liner has the web suspension straps cross each other instead of being tied in the center. This means the liner is a Vietnam era type, and not World War II.
Factual error: When Sergeant Howell is first introduced, the corporal assisting him calls the barracks to attention. You do not call "attention" for an NCO, however - you call "at ease."
Suggested correction: They are in boot camp. You stand at attention when they say you stand at attention. Especially when your Drill Sergeant walks in.
This is absolutely incorrect. In the United States Army, soldiers stand "at ease" in the presence of a non-commissioned officer (such as a drill sergeant). Soldiers only stand at "attention" when in formation or in the presence of a commissioned officer. Having served, I am very well acquainted with the appropriate procedure.
Suggested correction: When you are in basic training, if you are called to attention you come to attention...if you are told to bend over and scratch your 6, you do just that...these men are not yet soldiers.
Factual error: Some of the men (including Desmond) are seen using modern, reproduction canteens. They have metal wire chains while World War II ones use stamped ones and a silicon or rubber disk in the cap instead of a cork.
Factual error: The soldiers somehow have cool looking, perfectly fitting dress uniforms, on the day of their enlistment or before they've gone to boot camp. Not something they've have so quickly.
Other mistake: The navy bombardment opens fire and there are huge explosions. When they attack from the ropes they walk at least 50 yards with no craters, just flame and smoke. Awfully big guns for no holes in the ground .
Factual error: When the Japanese commander is committing seppuku near the end of the final battle, after he makes the first cut his second cuts his head clean off, and it can be seen falling to the ground in front of his body. While having a second perform this act was indeed commonly part of the ritual, the second was actually supposed to ensure that the neck was not cut cleanly through, i.e. He was supposed to stop short and leave the head attached to the body by a small flap of tissue. It was considered extremely undignified and unnecessarily messy for the head to come clean off and roll around on the ground. For that reason, it was important to choose a second who was a skilled swordsman.
Suggested correction: While factually you are correct, s**t happens...when does anything in war go as it's supposed to? Just because something is supposed to go a certain way and doesn't, doesn't mean it was a mistake in the filming.
Factual error: In the courtroom scene, The Judge (Philip Quast) wears the Legion of Merit ribbon in the Commander Grade (Crimson ribbon with silver gold bow-knot (rosette)) left of the purple heart ribbon. However, the Legion of Merit is only authorized for u.s. Servicemembers in the Legionnaire Degree (plain ribbon with no markers). The only US exception to this were Gen. Lyman L. Lemnitzer and 59 other officers who received the degree of Officer (gold rosette on ribbon), still a lesser degree than Commander.
Continuity mistake: The wounds on Desmond's face change size and position when he is reading the bible before they get back to the front.
Continuity mistake: While Desmond and Smitty are training and climbing the wood stairs the sun changes between shots.
Continuity mistake: While Desmond helps Dorothy to climb the hill the sun changes between shots.
Continuity mistake: When Dorothy finds the feather Desmond left in her book, she picks it up with her right hand and pulls the feather out with her left. She then sets the book down. When it cuts to the close up of the feather the feather is now in her right hand and the book has magically jumped of the table and into her left hand.
Continuity mistake: When Desmond and Dorothy are on the mountain top and kiss, the side to which they tilt their heads switches back and forth several times as the camera switches between looking into the face of one then the other.
Continuity mistake: When the Japanese man at the end stabs himself in the stomach, in one shot we can see there's no knife in his stomach.