When the boys get in the car at Jed's house, Dean is in the driver's seat but when they pull up to the gas station, Sam is driving.
When Sam shows Dean his drawing of the branding on Meg's and Henrikson's hands, the drawing is shown to still be facing towards Sam when the camera points to Dean's face and the back of the paper (22:03). However, the back of the paper is blank when Sam hands it to Bobby.
When Sam walks by the brown Plymouth Duster in the junkyard, it's trunk lid is ajar, open several inches. A few minutes later, he pries it open from a shut position with a crowbar.
Bobby refers to the last book of the Bible as Revelations but it is actually the singular - Revelation.