Continuity mistake: When Mandy falls inside the Porsche, the Indian toy is facing an 8 o'clock direction, a second later it's facing a 6 o'clock one.
Continuity mistake: During the scene where Nick unties Mandy, the TV in front of the kid swaps from being normal size to really tiny.
Continuity mistake: When the mother hands Adam the giant rattler, Nick swaps from being next to her to three meters to the right in a split second.
Continuity mistake: Before the microwave waves hit the baby, the yellow bowl on his table keeps changing positions all the time.
Continuity mistake: Adam's shoe laces magically tie themselves up when he is walking around in Vegas.
Continuity mistake: When Nick's mom faints, she is laid on the couch. Depending on the angle her head is either facing the right or the left side.
Continuity mistake: Nick spills milk all over Mandy's t-shirt, but in the next angle it's spotless.
Continuity mistake: Nick asks his mom is he looks like a nerd and combs his fringe. Immediately after, a different angle shows it messed.
Continuity mistake: In Las Vegas, when the baby leaves the car its position keeps changing between shots.
Continuity mistake: Adam feeds Nick a sandwich stretching on his chair and totally loses his balance, lifting an orange cushion underneath and almost falling off the chair. There's an abrupt cut and the kid appears repeating the movement, though now he's sitting straight, and the cushion is gone.
Continuity mistake: When Adam is watching TV, the stuff underneath, next to the white basket, keeps changing from tidy to messy between shots.
Continuity mistake: When Adam is throwing toys, the chair to the left of the screen keeps changing positions all the time.
Revealing mistake: When the family is running around trying to settle down the big Adam, Adam picks up Nick. From the back view, Nick is obviously a doll.
Continuity mistake: When Nick meets Mandy, the guy by her right has a towel on his shoulder which keeps swapping from thick to thin between shots.
Continuity mistake: When Adam escapes through the window, the state of the blinds he breaks changes between shots.
Continuity mistake: While the family is chasing Adam around the house, the time on the cuckoo clock changes drastically in less than a second.
Continuity mistake: When Wayne jumps on giant Adam and falls down his pants, when he lands on the floor Adam's shoes are clean but from the very next shot they are really dirty.
Continuity mistake: When Nick cries to Adam, "I'll fix you, you little punk" after he breaks the guitar, the scarf next to the hat changes from tidy to spread all over the sofa.
Continuity mistake: Adam is throwing toys all over the room and makes the ceiling lamp swing violently. In the immediate close-up the lamp is still.
Answer: She may have said goodbye to Adam but it just wasn't shown.