During the Thanksgiving after-dinner sequence. Everyone sings "Amazing Grace" accompanied by the sound of a harmonium. The camera pulls in to show Arlo playing a Fender Rhodes stage piano as if he is the accompanist.
The Rhodes is not an instrument capable of sustaining chords like a harmonium.
Throughout most of the scenes in the movie the length of Arlo's hair keeps changing lengths. In one scene Arlo's hair is long to his shoulders and in the next scene is hair is short to his collar, vice versa.
Arlo and Roger drive to the police station in Arlo's van, whereupon they immediately get arrested. However, after Alice bails them out, they ride away in the back of Alice's car, prompting the question, what happened to the van?
Early in the film Arlo goes "out west" for college (according to his bio he went to Rocky Mountain College in Billings, MT) and has an altercation with some bigots at a pizza parlor. There is a neon sign on the pizza parlor that advertises "Pizza and Grinders". "Grinders" is a New England name for "submarine" sandwiches and is rarely used outside of the area.
Although Arlo's mother says after Woody Guthrie's death that there will be "no funeral," a private funeral service was held the day after Woody died, after which he was cremated and his ashes scattered at Coney Island.
According to a published newspaper account of the incident at the time, as well as Officer Obie's own account much later, the envelope that provided the clue to the litterbugs had Ray Brock's name on, not Arlo's.
The outdoor scenes in Stockbridge, MA on Thanksgiving Day show brightly colored leaves on the trees. By late November, the trees are bare. This scene was likely shot during the first two weeks of October.
32'45'': Flipped shot: the bulb is on Officer Obie's right, and the word "chief" on Obie's hat appears like in a mirror. Two shots later, the bulb is on the left, and the hat reads "chief" in normal letters.