Continuity mistake: In the exterior front shots of Elliott's house there are some significant changes to the landscape in different shots. For instance, the two lampposts at the bottom of the driveway change to an entirely different style in some shots, and the huge garden boulders repeatedly vanish and reappear. Also, note when Michael takes off on Elliott's bike to go search for ET, the in-ground lamppost that should be beside the mailbox has vanished, but it reappears when all the government agents are setting things up outside the house.
Continuity mistake: Near the end after the mob goes over the cliff and Jim is chasing the horses through a snow patch, another rider on a light colored horse can be seen on the right. (01:36:00)
Continuity mistake: When Mr. Warbucks is talking to Miss Hannigan, he mentions adopting Annie. After the camera angle changes to see her reaction, the folded blue paperwork suddenly appears.
Continuity mistake: The sequence in which Dragon is chasing Mrs. Brisby through the field, up the tree and eventually into the mill's lake, watch his eyes. The original placement is (from viewer's perspective) blue on the right and gold on the left. When he chases her up the tree the gold one is visible on the right, it then switches back when the camera cuts back to a wide shot. This happens again a few seconds later near the lake.
Continuity mistake: In the scene just before the snowman comes to life, the clock in the hallway reads midnight. But a little later, when he is showing the snowman around the house and he is about to lead him upstairs, the clock reads 8:05.