While Mary reads "Peter Pan" to Gertie, her silhouette can be seen on the slats of the cupboard door. Her lip movements do not synchronise with the narration.
After E.T. appears to have died, a member of the medical staff is dictating a report and states: "Cardiac arrest was terminated at 1500 hours and 36 minutes". The term "cardiac arrest" denotes that the heart has stopped, so it makes no sense to claim that a cardiac arrest was terminated. The line ought to have been either: "Cardiac arrest occurred at 1500 hours and 36 minutes" or "Cardiac activity terminated at 1500 hours and 36 minutes".
Greg, a friend of Elliott's, asks why E.T. can't "just beam up", as they do in Star Trek. Elliott answers that "this is reality", implying such feats are impossible. Yet Elliott and his siblings had already seen E.T. use his telekinesis to lift, float and manoeuvre objects in mid-air. Moreover, Elliott himself was made weightless and swept through the air while he and E.T. were on his bicycle on Halloween evening, so he should have realised that "reality" as he understood it was altered in E.T.'s presence — since E.T. could, in fact, make even fairly heavy objects levitate at will, it was quite plausible that other scientist-like beings had the same means to hoist and transfer one of their number onto their spacecraft, and that their ship might also have been fitted with a tractor beam.
Elliott is handed some money and told to wait outside for the pizza delivery driver, which suggests the pizza has already been ordered and is on its way. Shortly afterwards, the boys ask him to make sure he orders plenty of pepperoni and sausage. He is later seen outside meeting the driver at the bottom of the driveway.
In the 20th Anniversary Edition, when Elliott shows E.T. the bathroom and then speaks to his mum on the telephone, the Coca‑Cola can alternates between designs. At first it bears the original 1982 styling, then it changes to the updated 2002 can design, and it continues to switch back and forth throughout the scene.
The shape and dimensions of the eye openings in E.T's ghost costume change several times, and this is particularly evident when Michael discovers the discarded costume whilst searching for E.T.
In the final shot of the spaceship's lift-off, all the people who had been gathered around it on the ground have vanished.
Elliott crashes his bicycle while chasing through the new housing estate, yet he is back with the group in an impossibly short space of time.
During the bike chase, one of the kids pulls off his balaclava and shouts, "We made it!" A horde of government agents then rushes into the road behind him. In the next shot of Michael's reaction, his friend removes the balaclava again and the agents hurry into the road once more.
When Elliott and his brother first attempt to drive off in the government van and are apprehended, the agents cluster around it and stand in front of the vehicle. Yet moments later the van pulls away with ease, despite there being no-one standing in front of it.
Whilst the boys are playing about the kitchen table, the cigarette and ashtray vanish.
When E.T. is left alone in the house and spells "nuisance" incorrectly on the toy, the rear panel has been removed, but in the following shot the panel is back in place. Later, as E.T. pulls the blanket carrying the "phone" components, the panel is absent once more.
At the end, as E.T. and Elliott embrace, when the camera is behind E.T., Elliott's arms are wrapped fully around him, but when the camera is behind Elliott, his hands are resting on E.T.'s shoulders.
E.T.'s potted plant briefly becomes much larger while Gertie and Mary are in the car, just before the bicycle chase begins. The plant then reverts to its original, smaller size when Gertie returns it to E.T. prior to his departure.
When Gertie waits at the rendezvous with the bicycle, the sun is on the verge of setting behind the mountains. There is, however, still ample daylight for the Halloween street scenes. In the next shot the sun appears considerably higher above a smaller foothill. Finally, when the children and E.T. meet up at the bicycle, the sun has just dipped below the mountain peak.
E.T. is portrayed as relatively large (he and Elliott are roughly the same height — at the end of the film E.T. hugs Elliott without Elliott having to stoop much), so he could not plausibly have been tucked into the front basket of the BMX-style bicycle; he would also have been far too heavy for the young, slight Elliott to pedal and keep the bike balanced with E.T.'s weight at the front.
When E.T. climbs aboard his spacecraft, Elliott's mum rises twice, and Elliott is shown alternately holding and not holding his dog by its collar.
When E.T. walks about outside on Halloween, the eye-holes in the sheet are set far apart and only one lines up with his eyes. However, the point-of-view shots seen through the sheet show the two eye-holes positioned close together and aligned.
When Elliott detaches the tunnel and the two men from the rear of the van, the men's air hoses remain attached to the van as it drives off, but a second later they have disappeared when the van is seen from a different camera angle.
At the start, while the men are searching for E.T., the keys on the "Key Man" switch sides from shot to shot.
When Elliott belches in the classroom, his pencil vanishes over several cuts. The papers on his desk shift position repeatedly.
When Elliott believes E.T. is dying and speaks to him through the box's window, the towel wrapped round Elliott continually shifts — at times snugly encircling his neck, at others exposing part of his left-hand side.
Near the end, as the children cycle down the hill, they pass a police car and, after rounding the corner by a housing estate, you briefly see Elliott — or the rider in the red hoodie — come off his bike. In the next shot they are cycling on as though nothing has happened.
After Elliott and E. T. have finished saying their goodbyes, Dee Wallace can be seen in the background standing up (next to "keys"). The subsequent shot, a medium-distance one, once again shows Wallace rising to her feet.
As the boys are pursued by government agents, the film repeatedly shows the same houses and road junctions from different viewpoints.
Through the railings you can make out the silhouette of the stunt performer wearing the E.T. gloves as Elliott tempts E.T. with Reese's Pieces.
As Michael guides Mary into the bathroom where Elliott and E.T. are lying ill, the camera pulls back on a dolly, sweeping past and visibly disturbing an indoor bamboo plant.
When Elliott, Michael and E.T. reach the park after fleeing the scientists, a ramp is visible where they drive over the kerb.
Just before E.T. reads the Buck Rogers comic, he yawns and rubs his head. As he does this, you can just about make out the crew moving in the corner of the oven's reflection.
The street the boys turn onto during the pursuit — at the moment one of them says "we made it" — is not the same street they had previously entered. There ought to have been houses there, but instead there are only trees and cars.
When Elliott falls asleep outdoors while looking for E.T., the Moon sits directly behind him; several hours later, when he is woken, it remains in the very same position.
E.T. demonstrates his telekinetic ability to lift himself into the air on two occasions, most notably towards the end when he helps Elliott, Michael and his friends evade the authorities. He could have simply used those powers to return to his spaceship before it departs at the start of the film.
Elliott and Michael disguise E.T. as a ghost on Halloween to convince their mum it's Gertie. Since E.T. looks considerably smaller beside Elliott and Michael than Gertie would, it ought to have been obvious it wasn't her.
Seeing as Elliott's house had been cordoned off by the police and placed under quarantine, Elliott and Michael ought not to have been able to steal the van and make off with E.T.
When 'Keys' enters the 'clean room' created for E.T. and Elliott, he and the others wear 'clean suits', yet the tubes protruding from the helmets lead nowhere — there isn't even a filter attached — so they are effectively breathing contaminated air and the suits are pointless.
As the boys cycle away from the authorities, the stunt doubles standing in for Elliott and his friends are noticeably far too tall to be children.
One of the boys mouths Elliott's line, "Nobody go out there."
While E.T.'s being pursued by government agents and hurries back to the spacecraft, a pole can be seen behind him, apparently pushing him along. This happens immediately before the extraterrestrial is shown inside the craft as it's departing.
While the boys are trick-or-treating, the eyeholes in E.T.'s ghost costume do not align with the point-of-view shots.
