Other mistake: In the opening song, the dolphins sing: "If we could just change one thing, we would all have learned to sing", however the subtitles on the DVD say "lungs to sing". As a side note, dolphins do indeed have lungs.
Continuity mistake: When Ford is drinking in the bar, the amount of beer in his glass goes down mid-drink.
Trivia: At the very end of the film, when the group uses the Improbability Drive to go to the Restaurant at the End of the Universe, there are a lot of images that flash onto the screen when the drive is activated, so in the other parts of the film. In this case, the very last image shown is the face of Douglas Adams, the creator of the Hitchhiker series.
Question: How did Marvin get the point of view gun to function the way it did (The front part popping open and firing a huge, wide-coverage blast)? That never occurred any other time the weapon was fired, and Marvin couldn't have known how to do it since they had recently discovered the gun.
Answer: Marvin does have a brain the size of a planet! He could have easily worked out the controls or directly interfaced with the weapon.
Sierra1 ★