Revealing mistake: When the Porsche Cayenne is lifted out of the water at the scrap yard then placed on the ground, if you look through the gap between the front passenger wheel you can see the engine is removed from it.
Revealing mistake: When Jerry jumps out of the building to escape the FBI, when he lands it does not look like Shia LaBeouf but a double.
Revealing mistake: When Jerry is in the tunnel and Morgan blows up the drone, Jerry hides behind the front of a car. Then he runs to the back, but he is shown again at the front of the car.
Chosen answer: I'm pretty sure it's to prove to the people watching the movie and to both Jerry and Rachel what can happen if they disobey, as after this event they followed the orders from ARIA closely.