The film takes place in the early 1970s. Outside the motel there's a car with an old, battered "D.A.R.E." bumpersticker. But the D.A.R.E. (Drug Abuse Resistance Education) program was not founded until 1982.
In the hitchiking scene, FH predicts he will be picked up by a family driving an Oldsmobile, and when he is picked up it is presented as if he predicted correctly, but the car they are driving is a Chevrolet, not an Oldsmobile.
According to the director and screenwriter, many continuity mistakes were intentional. FH misremembers the stories each time he tells them and so there are intentional differences inserted when shots reappear in the film.