Continuity mistake: In the scene where Veronica comes to Billy's house, tosses him in the pool and starts beating him up, watch the people on the side of the pool. First, the chubby guy and Frank are sitting in lounge chairs and you see a third person's legs on one of the chairs. Then the next time they cut to them, the third set of legs is gone, and Frank is lying on the chair where the legs were. When they cut back again, Frank is back in the first chair and there is no third pair of legs.
Suggested correction: Almost nothing in the entry is true. Jack (the "chubby guy") is never in a lawn chair, he's on the ground. Frank isn't sitting on the lawn chair, he's lying on it. The "third person" is passed out on the ground, his legs aren't on a chair. And the passed out guy remains in the same position, just sometimes he's off camera due to the close shots of Frank and Jack. Frank stays lying on the same chair he was always on.
Revealing mistake: When the car is falling off the cliff you can clearly see that there is 1 person in the car, it's not packed with the whole family like before.
Suggested correction: There's not actually any people in the car when it goes off the cliff. But the car is packed with multiple dummies to simulate the entire family.