In the scene where Jake first meets Neytiri and attempts to thank her, he takes hold of her arm, but the sound effect for the grab isn't synchronised — you can hear it a couple of seconds before he actually grabs her.
In the climactic battle, Colonel Quaritch issues the command "Weapons Free" and then instructs his forces to engage all hostiles. However, "Weapons Free" permits firing at any target not positively recognised as friendly. The appropriate order for engaging only targets that have been positively identified as hostile is "Weapons Tight".
In one of Jake's video logs, Grace is visible in the background carrying out an experiment. At one point she draws liquid into an Eppendorf pipette and, while moving it to the intended receptacle, she inverts the pipette — an action that would likely cause serious harm to it.
"Severely damage" is somewhat overstated. The pipette would more likely become contaminated, depending on the nature of the liquid, and a proper decontamination would be sufficient.
Jake is in the process of being reborn into his permanent Na'Vi avatar body; his human form is shown without an oxygen mask over the face. Because Eywa takes a considerable amount of time to carry out transfers of souls, his human body would have perished from oxygen deprivation.
The colonel's robot has a rear-view mirror. In exterior shots the mirror appears positioned very close to his head, yet interior shots show ample space around his head and the mirror is absent.
As the dragon gunship lifts off to join the formation for the final battle, it is shown carrying eight white missiles on eight weapon pylons — four on each side. Later it is seen with just four missiles on four pylons, two on each side.
In the scene where Jake wakes from his link and Grace asks, "Is the avatar safe?" and he replies, "Yeah, Doc, you're not going to believe where I am," her hand is resting on the top of his shoulder. Yet when the camera cuts back and forth, her hand switches to the side of his upper arm and then back to the shoulder with no time shown for such a movement.
When Jake's bonding with the Mountain Banshee for the first time, his hair can be seen shifting from lying over his right shoulder to lying over his left between shots. (His hands remain on the Banshee the whole time, so he has no opportunity to change it.)
When Jake first guides his legs into the linking machine, Grace's hands are seen close to his legs as if about to help. However, in the following shot she is a few feet away and then moves in to assist with lifting Jake's paralysed legs.
After their first meeting, Jake follows Neytiri to thank her; she is holding her bow and an arrow in her right hand. After she knocks him to the ground and he attempts to thank her, the arrow briefly vanishes from her hand on-screen for a few seconds. A short while later the missing arrow reappears in the same right hand that had been holding the bow the whole time.
As Quaritch reprimands Jake for kissing a Na'vi, Jake tilts his head to the right; in the very next shot his head is positioned straight ahead.
During the sequence in which they fly north in the mobile link-up trailer after Grace is shot, Jake Sully covers Grace Augustine with a blanket and leaves it folded at the top. Subsequent shots inconsistently show the blanket alternately lying flat with no folds and then with visible folds.
Mo'at stabs Jake with a knife to examine his blood. In the following shot she licks the blood once more.
She is double-checking — she has never tasted artificial Na'vi blood before.
Neytiri's breasts vary in size over the course of the film.
In the scene where Parker is shown playing golf on the indoor golf course at the RDA, the first time he strikes the ball there are two other balls lying next to one another on the course. In the following shot the two balls are further apart, and in the shot after that they have returned to their original positions.
In Jake Sully's report, just before he becomes one of the tribe and "comes of age", the displayed time is 23:00 and the log number reads 007, which is inconsistent because the previous report shown was 012.
When Seze first emerges from the tree, Neytiri's ponytail is tossed over her left shoulder, implying it ought to hang down the front of her. In the next shot, however, it is hanging down her back.
In Avatar, every robot stays upright and remains motionless until its operator issues a command to move. Yet when Neytiri kills Colonel Miles Quaritch, his machine topples to the ground as if it has been destroyed.
As Hometree begins to topple, the long, straight vines hanging from its branches are depicted as remaining perfectly vertical, much like a heavy pendulum. In reality, those lightweight vines would be pulled upwards and ought to swing back, trailing through the air behind the moving treetop.
Whilst acknowledging it's an extraterrestrial world, any sizeable planet positioned so close would produce marked gravitational consequences — enormous tides, planetary quakes, erratic weather and tectonic movement. The neighbouring body to Pandora, however, seems to exert no influence.
Sully is informed he was selected because he and his twin brother "share the same genome." Yet studies have shown that, on average, twins differ by at least five mutations in their DNA.
All human avatars have five fingers and toes, whilst the natives possess only four. This detail was meant to emphasise the subtle differences in the avatars arising from the blending of human and native DNA.
When Selfridge lectures Grace in his office about the company's aims on Pandora (extracting 'unobtainium'), he ends with the Spanish phrase "Comprendo?". This is grammatically incorrect as it would translate to "Do I understand?". Addressing Grace, he ought to have said "Comprende?" ("Do you understand?"). His slip in language use, however, highlights his lack of respect for other cultures.
It is incorrect to suggest the helicopter‑like craft sounds like an ordinary helicopter: high‑speed, framed propellers produce a distinctly different, buzzy yet smoother noise at a higher pitch. However, we know they operate in an atmosphere quite unlike Earth's (people must wear masks), and are lifting a vehicle in gravity that differs from Earth's (the humans are described as working in low gravity), so we cannot reliably state what these propellers would actually sound like. The familiar 'whop‑whop' effect used comes from the interaction of the "air" flow of a two‑bladed main rotor — as on a Huey — with its tail rotor. Other helicopters use four‑ or five‑bladed main rotors and tail rotors with more than two blades to remove that characteristic sound.
When Parker Selfridge tries to explain the 'Blue Monkeys' situation to Jake, he says Hometree stands on the richest Unobtanium deposit for 200 clicks in any direction. His phrasing suggests that even richer deposits lie farther afield. It would be much easier to relocate the camp to another deposit than to move the Na'vi, yet Jake tells the Na'vi that more humans will come "like a rain that never ends". Thus it is reasonable to expect future camps to be established on other deposits, and uprooting the Na'vi would merely waste resources.
When Jake's Avatar is being chased and leaps off a cliff into a waterfall and river, both he and his clothing are clearly drenched. After he clambers out he fashions a spear from his dagger. A few hours later he wraps his outer shirt round the spear tip, dips it in a viscous, amber-coloured fluid that he somehow knows is flammable, then lights it with an astonishingly dry packet of sulphur‑tipped matches. We can safely assume that in two hundred years the design of survival matches will have improved.
Although Pandora's atmosphere contains far less oxygen than Earth's, the colour of its flames suggests an oxygen level comparable to Earth's. The colour of a flame also depends on the substance burning, a principle exploited in fireworks.
While Jake is recording his first video log entry, he shifts the recording camera slightly to get a clearer view of his face and glances at a screen to his right to check that he's centred his face correctly. In the very next shot he is looking straight ahead at the camera. This is not a continuity error; he has checked the angle and then looks at the camera so it does not film the side of his face.
Magnetic fields powerful enough to levitate mountains would disrupt — if not entirely obliterate — aircraft avionics. Flying into or close to such fields would be impossible, as they would render aircraft uncontrollable. Avionics two centuries hence are more likely to be optical rather than electrical.
Possible continuity error: In one scene where Parker Selfridge is handling the Unobtanium in his office, the name and title on the glass wall look as if they were applied from the inside, since they are readable left-to-right. Normally, an office name and title are applied from the outside and therefore would not be readable left-to-right but would instead appear reversed, like a mirror image. The technique for this is a pattern of dots that are black on both faces; selected dots are then coloured on one side for the "inside" view, and different ones are coloured on the other side for the "outside" view.
The film never clarifies whether Unobtanium is an element or a compound. This matters because, if it were an element, one would expect it to occur in substantial quantities across the whole planet and on neighbouring planets, moons and asteroids. If it were a compound, it could be synthesised, which might reduce or even end mining on Pandora in favour of sources on Earth or much closer to it.
Since the film's central premise is that Unobtanium is scarce and urgently needed on Earth, the story pays little attention to how or why the substance exists, which lessens its apparent significance. Unobtanium is likely an element, and the deposit on Pandora could be the result of an exocomet impact originating many light‑years away.
(at around 1h 13 mins) Neytiri's English seems strangely limited when she says "this you", despite displaying a much more sophisticated command of English earlier in the film (or, more simply, the fact that most English sentences require a verb). The previous line was "I came" (with "came" being the past tense of the irregular verb "come"), yet she had no trouble recalling either the verb or its tense.
Many people can understand a language quite well without being able to speak it fluently.
When Jake awakens from cryogenic sleep he says "It doesn't feel like six years." But as he is ejected from the pod the medic attending the passengers announces "You have been in Cryo for 5 years, 9 months and 16 days." That indicates they were only in cryogenic sleep for five years rather than six. However, if one is rounding to the nearest whole year, six would be a closer approximation than five — or should he still say "5 years" even if the actual period were 5 years, 11 months and 29 days?
The heavy craft that descends into Pandora does not require wheels. In orbit, it would weightlessly dock with & undock from the transport vessel; on Pandora it takes off & lands vertically. However, many large helicopters, including that of the US President, are fitted with wheels, so they can be towed if necessary.
When Sully becomes lost on his first field trip, it seems rather odd that his hugely expensive avatar body — so valuable that an untrained, inexperienced invalid soldier was flown across light‑years to use it — contains no implanted tracking hardware to prevent precisely the sort of accidental loss he suffers.
At roughly 110 minutes into the film, Trudy powers up the engines of her craft before everyone is on board. This instantly alerts the military authorities that she is departing without authorisation. Consequently, the Colonel fires at Grace, wounding her. Had Trudy waited to start the engines until everyone was aboard, it is likely Grace would not have been hurt.
Probably, had she known that, she would have waited. But she didn't.
When Jake first attempts to persuade the Na'vi not to fight, and Tsu'tey pushes him, Tsu'tey's eyes appear colourless and grey. In the scenes immediately before and after, however, his eyes are distinctly yellow.
After Quaritch breaches the command centre to open fire on the escaping prisoners, several members of staff are visible behind him, moving about as normal without their exopacks.
During the scene in which the Na'vi attempt to transfer Grace from her human body into her Avatar after her death, when one of the Na'vi leans over to check for signs of life in the Avatar form, her eyes can be seen to twitch briefly even though she is presumed dead.
Jake approaches the Tree of Souls to pray to Eywa with his ponytail hanging down his back as usual. He kneels at the tree with the ponytail still in the same place; he then reaches down for something, the shot cuts, and the ponytail is suddenly in his hand. This was probably done to match Sam Worthington's performance, since he wasn't holding it as he came up to the tree and it would have looked odd for him to be holding it in a way that conflicted with the motion-capture data.
When the avatars lie on the stretchers, just before Jake and Norm enter them for the first time, the camera pans past and Jake's avatar twitches the toes of its left foot.
At the start the spacecraft is shown moving backwards because Pandora appears in the mirror at the rear of the craft, and the two smaller craft are joined to the mirror tail-first. In the following shot they are shown attached nose-first to the mirror.
