Revealing mistake: When David enters the food robot to escape, he makes a left at a cop car with the license plate 11385. A few moments later, he passes the same exact car going in the other direction. (00:41:40)
Revealing mistake: In the scene where Max challenges David to navigate the ship on his own, fingers are seen controlling the Puckmarin's movements at one point. (01:04:05)
Revealing mistake: Many times during the movie, when there is a close-up of the puckmarin, tiny wires can usually be seen attached to its arms.
Revealing mistake: When introduced to what David calls "Popcorn", the wires moving the puppet are visible.
Answer: Carolyn wouldn't have wanted David anywhere near the UFO as it could've been dangerous, so it's safe to assume that "Max" programmed the R.A.L.F robot. Although Carolyn didn't have anything to do with with David's escape, it wouldn't have escaped unnoticed that the R.A.L.F robot was in the hanger where the UFO was. Given that she's always the one with the R.A.L.F. robot, it's safe to assume she was acting worried that she'd be blamed rather than acting "shifty"