When Richard Dreyfuss (Neary) is chasing the UFOs into Ohio, he slams on his brakes as the lead police car goes off a ridge into a field while the UFOs ascend to the sky.

First, that part of the country is flat with no such overlooks.

Second, the police cars are shown, closeup, screeching to a halt next to Neary's truck, parked parallel to him.

In the next shot, a wide shot, Neary's truck is out of position, its nose pointed nearly perpindicular with the first parked police car, not parallel to it as the previous shot indicated. The truck isn't slightly out of position, it's WAY out of position.