Factual error: After the Death Star, when TIE fighters are attacking the Millennium Falcon, each time one explodes at high speed, the debris and the fire does not keep moving.
Factual error: Melanthius claims to be friends with Archimedes, who died in 212BC. Yet the movie must be set after the birth of Mohammed, in 570AD, as it contains references to Islam. Only out by at least 783 years.
Factual error: In the opening shot of the film, The first verse of the poem is recited. There is a very minor mistake in the subtitles on the region 1 DVD. Instead of "...in the wabe: All mimsy..." they read "...in the wabe. All mimsy...". (00:00:10)
Factual error: In the hypnosis scene, when father Marrin is crossing himself, he is doing it the wrong way - from right to left. (00:20:40)