Other mistake: Old Ben duplicates Jenny so she can accompany him to his home planet. As he can turn into anything, he should be able to approximate her height. When the now twins walk out, the girl on the right is a couple of inches taller than the girl on the left. Not only that, but her hair is noticeably darker.
Other mistake: Chambers asks what time it is on Earth, a strangely vague question to which the Kanamits grant an equally odd answer: on Earth, it is noon. It can't be noon everywhere on Earth at once. While it can be fancifully explained away ("They somehow knew to answer for the time zone he was taken from"), it still jars the viewer, because neither Chambers nor the aliens, both highly intelligent, should make this sort of imprecise mistake. Both director Richard Bare and Damon Knight, author of the original short story, confirmed this as a scriptwriting error that should have been caught before shooting began. (00:02:15)
The Arrival - S3-E2
Other mistake: As part of the story line, three men see different tail numbers on the plane. However, the first and third sets of numbers are printed on a big sticker, because the numbers are a different style than the second set. Also, they used two different planes. The second tail number is N67588, which should be on the bottom of the wing, but that number is N107932.
Other mistake: The Kanamit have to lower their heads to pass through the doorways on their own ship.
Suggested correction: Just as astronauts on the International Space Station and the Shuttle before that had to.
