Other mistake: When Quin is cutting the plane that's stuck in a tree, he uses a saw, that looks brand new. He's just been chased by pirates and jumped off a cliff - where did he get the saw from? Anything in the plane would be rusty by this point.
Other mistake: Watch Harrison Ford's hair throughout the film. When they are making the rafts out of the plane, you can see that he has had his hair cut. I never knew that they had a barber's on that island.
Answer: Motu Nui is a real life island, the name means "large island" in Maori. Most likely that is the source of Lego's inspiration for the name. While it is certainly possible that whoever came up with Mata Nui first heard the name Motu Nui in this movie, it is unlikely. Motu Nui is a fairly well known island and also shares its name with a settlement in New Zealand. A fictionalized island called Motu Nui is also the home of Disney princess Moana, which obviously came out after Bionicle but speaks to how well known the name is.
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