Deliberate mistake: At one point during the big escape chase scene, Finnegan takes a turn and the jet-ski he and Trillian are on side-swipes a wall and it's clear that they're about to fall off. The film cuts away briefly and then we see them and they're zooming along again as though nothing happened. The scene is portrayed in real-time so there's no way they had time to spill, get back up again and build up enough speed in the time between edits. Slightly sloppy editing. (And this is not referring to the other moment in another mistake where the same thing happens when they exit the boat. It actually happens twice during the scene - that moment and this one).