Continuity mistake: When Gertie places a pot of wilting flowers onto the Radio Flyer wagon, an 'enter' sign can be seen on Elliott's bedroom door with a handwritten paper saying 'do not' taped upon it. After she knocks, Mike opens the door to let her in - but the 'do not' paper is now tucked behind the 'enter' sign instead. (00:37:00)
Continuity mistake: Many of the night scenes take place in the back yard, or in the cornfield which is shown to be behind the back yard. Daytime shots show the house to be in the suburbs, on a hill, with no cornfield or possible space for a cornfield.
Continuity mistake: After being discovered by Elliott in a cornfield, E.T. panics and escapes through the back gate, which closes by itself. But in a following shot, the gate closes again. (00:14:45)
Continuity mistake: When E.T. Is at home with the speak and spell, the back cover is missing as he is working on it. In the next shot, the back cover is on it again.
Continuity mistake: While ET is watching Mary read the story of Peter Pan to Gertie, in the shot from outside the closet we see Elliott using his left hand to close the shutter slats, but in the next shot inside the closet it is Elliott's right hand closing the slats.
Continuity mistake: When Mary gets her first look at an ailing E.T. lying on the bathroom floor, she panics then hurries everyone downstairs - leaving E.T. behind. Moments later one of the astronauts happens upon E.T. and now a bright pink bath towel can be seen draped over the bathtub's edge, which wasn't even there to begin with. (01:16:00 - 01:17:55)
Continuity mistake: In the scene on Trick-or-Treat night, Elliot and E.T. go to the forest so that E.T. can set up his communication device to "phone home". While they are there, Elliot is appealing to E.T. for him to stay, saying he will get used to it. While he is talking to E.T. he is inches away from his face. But in the very next shot it shows E.T. looking around, staring into space, with Elliot nowhere to be seen. But the next shot shows Elliot is in E.T.'s face again just as he was two shots before.
Continuity mistake: When Elliot opens the solar system book, ET's finger is on the edge of the page. A frame later it's several inches above.
Continuity mistake: After Elliot frees the frog, notice a group of kids in the background with a blonde girl in a blue dress on the left: they're either watching Elliot in awe, or looking down at their books. This changes back and forth several times.
Continuity mistake: When Elliot burps, the pencil on his desk disappears between shots. Also, the paper swaps from laying on the edge to several centimeters away.
Continuity mistake: Throughout the movie E.T.'s fingers are shown to be very long, thin, and boney. But in the final scene, when Elliot and E.T. are saying goodbye, E.T. reaches down to pick up the flower pot to take with him. The camera shows his hands picking up the flower pot but they appear the size of human hands wearing gloves, not the long skinny fingered hands we saw during the entire movie.
Continuity mistake: When Elliot's mom leaves to school and Gertie says ET can talk, the cupboard behind her swaps from lit to unlit between shots.
Continuity mistake: When Keys turns around to see what's rustling in the bushes behind him, his flashlight swaps hands between frames. (00:05:50)
Continuity mistake: When Elliot opens the book with the solar system, the book pages are folded, yet a frame later, from a different angle, the book is opened wide.
Continuity mistake: When Gertie replies she's going to Elliot's room, she swaps from holding her trolley with one hand to two.
Continuity mistake: While ET takes a bath, Elliot - face and hair covered in Coca-Cola - hangs up on his mom and goes back to the tub. When the angle changes his face and hair are dry.
Continuity mistake: When E.T. is in the kitchen reading comics, he glances over at the TV then takes a look at the coffee table which has, among other items scattered on top, six pack rings. A few shots later E.T. is at the coffee table working to create a communication device, but now there's one can of beer attached to the rings. (00:48:05)
Continuity mistake: When ET is walking with Elliot and his brother trick-or-treating, we see several shots from ET's point of view of people walking toward him. In all of the following shots however, none of the people that were walking toward him can now be seen behind him as they should be. It's not a montage either, these scenes are to be taken that they are occurring in real time.
Continuity mistake: After E.T. clicks the TV set on, the way he holds the remote control differs between cuts. (00:46:20)
Continuity mistake: Home alone, Elliot talks to ET and says "Human. Boy. Elliot" and right then he swaps from standing one meter away from the bed to leaning against it.
Chosen answer: They actually are smoking and there are cigarettes on the table.
Mike K