Revealing mistake: When the channel 6 crew member is telling April they should go, his hand disappears for a frame.
Revealing mistake: The "hostage" episode reuses footage from the "Dinosaur" episode, which doesn't totally fit. When the giant crabs attack and destroy the group of houses on the island, the longshot of the damage is recycled from the earthquake episode - including an earth fissure, something the giant crabs wouldn't and probably couldn't have done.