If, as Kayla says, the passenger manifest shows the scientist is sitting at the red X with Snake Doctor to his left, then the manifest is either wrong or, bizarrely, the cabin layout is shown upside-down. The chemist is actually sitting on the left-hand side of the aircraft with Snake Doctor to his right. If the cabin layout is inverted, that flies in the face of all convention, where the cockpit is *always* shown at the top with the passenger cabin below it.
While standing in his new kitchen area with Tiffy, Mack gets a phone call. He answers the phone "Go for Gerhardt." This negates the purpose of all the families being given new last names to memorize, especially when the next-door neighbor comes by shortly after to tell Tiffy she heard everything through the thin walls.