Factual error: When Glass saves the Indian girl from the Frenchmen the flintlock pistol he gets off the Frenchman fires multiple times without reload, as it does later while being chased by the Indians.
Factual error: While arguable that Glass could have survived the numerous attacks upon his person (a momma grizzly, cold, hunger, starvation, etc.), his lengthy immersion in an icy river and subsequent grounding and re-warming boggles belief. While hypothermia is considered to be the cause of death in such instances, the fact is that within minutes in extremely cold water, a person becomes unable to perform the simplest of motions as the extremities shut down...and they drown. In addition, Glass hauls himself from the river and shortly thereafter is seen in his warm, dry outfit, heading out for new forms of physical and emotional abuse.
Factual error: Hugh Glass is wearing a coat with a zip when the bear mauls him. Zippers had not been invented at that time.
Factual error: The firearms of that era did not use smokeless propellant (i.e. gunpowder). None of the shots fired in this film produced anywhere near the black smoke that would have been realistic.
Factual error: Fitzgerald tells a story about his father setting out with a party of Texas Rangers across the Llano Estacado. There are two problems with this: first, the Texas Rangers were first formed in 1823, the same year the movie takes place, and consisted of around 10 men who were not yet known by that title. Second, the Llano Estacado is in the Texas panhandle, an area almost completely unexplored by Anglos at the time (and nowhere near the area where any rangers lived).
Suggested correction: A couple of errors here, both possibly minor. He said it was in the San Saba hills, OK still Texas but not Llano. Also, yes 1823 was when the group of 10 was officially put together and offered payment as 'Rangers' but the same men, and more, had been operating unofficially as rangers in the same areas for several years. So, it may well be this which he is referring to in his 'story' passed down from his old man.
Continuity mistake: Hugh's wounds change from when he cuts open the horse to the ending when he is sitting inside the shack. Specifically, a wound on his right shoulder is there and gone between those two sequences. His back wounds also change considerably.
Factual error: When the Indian band finds the body of Glass's son, one of them clears the snow off his face and touches the skin. The skin is easily indented by the touch, like the skin of a living person, This scene is in the winter in the high frozen mountains. The boy had been dead for at least a day, and the body should have been frozen rock solid.
Continuity mistake: When Bridger refuses payment for staying with Glass in the wilderness, his share of the money makes several mysterious movements on Captain Henry's desk throughout the scene. Although we see Bridger's share being handled only once, it goes from near the edge of the desk where Captain Henry placed it, to the edge of the desk in front of Bridger, to one moving bill in the middle of the desk, to all the money having disappeared from Henry's desk. (01:32:00)
Continuity mistake: If you look closely at Glass' face cut when Fitzgerald is biting his earpiece off, it is not bleeding when it should. In fact, it looks like the blood has been painted on his face.
Factual error: Stars in the sky are misplaced. The constellation Orion is on the wrong side of Pleiades and Taurus. In the movie Orion is placed above and to the right of the other two. In actuality, it is below and to the left of them in the sky. It appears that Orion was pasted into the frame, since the other constellations appear in their correct locations with respect to one another and the moon. (01:16:10)
Revealing mistake: When a force 10 gale is blowing and the CGI snow is horizontal... ... none of the trees move one bit, not one.
Visible crew/equipment: As Captain Henry rides off towards the end, there is a propane burner/heater on the ground to the left between the pine trees that he rides right past. (02:08:35)
Continuity mistake: When Glass and Fitzgerald are fighting at the end, watch closely as Fitzgerald pulls the knife out of Glass' knee after stabbing him and you will see the knife is soaked in blood. But it becomes clean seconds later before Glass stabs Fitzgerald in the stomach.
Continuity mistake: At the end of the movie, when Glass is chasing Fitzgerald, at the top of the hill before they both plummet to the edge of the stream, you can easily see the stream current below moving right to left. Then, after the fight scene, when Glass is presumably returning back up the hill to his horse, you can again see the stream, but this time the current is moving left to right - as if the camera was now filming Glass moving up the hill but now on the other side of the stream.
Continuity mistake: The appaloosa horse that he gets after saving the Pawnee girl is being ridden bareback, but when he jumps off it before jumping off the cliff there is a saddle under the Buffalo hide - the stirrup is visible.
Continuity mistake: When Glass goes into the river to escape from the chasers, there is a bandage on his head. He loses it after the waterfall, then somehow the bandage comes back. When he manages to grab some wood to save himself, the bandage has gone again.
Continuity mistake: When he falls into water there is no snow around the river, but 10 seconds later there is some.
Deliberate mistake: At about 1:49 in the movie, Glass is awakened by an attacking force of Arikara, and he fires his single-shot, muzzle-loading flintlock pistol at the nearest one coming at him. Then he runs to his nearby horse and flees, turning back to fire the gun a second time immediately. No reloading and no second gun on his person. It never leaves his hand; he's whacking the horse's rump with it to goad it on as soon as he jumps on it. And then he fires that same gun another time in a matter of seconds. (01:40:00)
