After the gang is chased by the Wiki-Tiki, they settle near a waterfall to talk. When Daphne first sits down, she puts both of her feet in the water. However in her next shot, she has on in the water and the other one under it, with the bottom of her bare foot almost completely facing the camera.
The large boulders that knock the Wiki-Tiki down, after Shaggy and Scooby act as bait, suddenly disappear.
Frank Welker's credits include "Interviewer." This character does not appear in the film. He is the guest character of the short film An Evening with the Scooby-Doo Gang (2005), included on the original DVD of this movie.
The first shot of one of the tourists telling Ruben why it's a good time to leave, the writing on the left side of Laluna Real Estate is backwards.
Contrary to the opening scene, Hawaii has no hummingbirds. It has honeycatchers, which look superficially similar to hummingbirds, but are very distinct.
Ruben's company is variously called Laluna Real Estate, Laluna Realties, and Laluna Realty.
Shaggy says that Scooby is hanging "20", but he is seen to have 16 toes rather than 20.