Continuity mistake: When Dahmer gets upset and tries to tackle the wrestler, he is thrown on his back and grabs the guys shirt. The shots after that switch between holding the shirt and not holding the shirt.
Other mistake: Jeffrey gets pulled over by a cop. He shows his license to the cop and the date of birth is the late 1990s, but he was a young boy in the 70s.
Visible crew/equipment: At the store, when Dahmer is buying the knife, you see a boom mic at the top of the screen.