Factual error: Zippo lighters are sold dry, no fluid when new.
Factual error: When the FBI agents are shooting Jason, 2 things happen that shouldn't, 1. His machete is shot but doesn't move, the force from the bullet would cause the knife to move. 2. When the bullets hit the knife, they cause sparks, bullets never cause sparks when they hit metal.
Factual error: Although taking place in North Dakota, the Jeep and cop car have the older Illinois plates.
Factual error: Detective Beck's daughter states that she had not seen her father for several years. That he lived as a hermit and did not let her in. Then why when she goes with the good alien to where her father used to live, she has the key to get in?