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 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 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: 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.
Continuity mistake: When the kids and the mother go outside to see what scared Elliot, ET's footprints on the sand are smudged. When the shot changes they're neatly marked.
Continuity mistake: When Elliot shows up behind the fridge his mom kneels down and puts her head on his chest. From the opposite angle she is standing taller, with her head by his right elbow.
Continuity mistake: The weather during the end chase changes three times. When they first leave it is full on sunny. When they arrive at the playground it is overcast. The next scene it's sunny again.
Continuity mistake: When ET's spaceship takes off and starts flying, the sky is red, a shot later it's blue.
Continuity mistake: At the end, ET's finger glows and he says "I'll be right here" but in the immediate opposite angle the finger's not glowing.
Continuity mistake: When the movie starts and ET is about to arrive to his spaceship with the cops behind, the scenes involving ET and the cops are filled with smoke, the ones with the spaceship are smoke clear. This swaps back and forth.
Continuity mistake: When the movie ends and the spaceship takes off, all the people in the forest suddenly disappear.
Continuity mistake: When Elliot says goodbye to dead ET, his robe swaps from open to closed around the neck.
Continuity mistake: When Gertie first meets ET his neck is either stretched or not depending on the angle.
Chosen answer: They actually are smoking and there are cigarettes on the table.
Mike K