Carmen calls for "rebreathers" in the Drangonfly sub. However, when she and Juni are swimming, they release bubbles associated with standard scuba respirators. Rebreathers recycle much of the gases in the system, reducing or virtually eliminating bubbles.
When "falling" into the volcano, Carmen asks Juni how long they have been falling and he guesses "about 3 hours". He should have known that they couldn't have been actually falling for that length of time as it would only take 42 minutes to fall right though the Earth.
When Gary and Gerti "bounce" onto the island and Gary says "I'm gonna zap that sucker to bits!", he hits his watch. It makes an electronic beeping sound, although it was stated that electronics don't work on the island. The watch would have needed electricity to make those noises.
When the President's daughter is on top of "The Juggler", Carmen is at the control panel, and Gerti asks her what she is doing. She answers "I'm trying to stop the ride". However, Carmen went to the panel before the secret service officer started the ride again. However, trying to stop the ride isn't necessarily the reason Carmen went to the panel in the first place.
In the party scene, when all the metal objects are flying up to the magnet, you see china plates going up too. However, in an agency like the O.S.S., it's just possible that the plates are actually metal objects (such as weapons) disguised as China plates.