Continuity mistake: Before the Roadhouse fire, Ash and Dean are talking on the phone. Ash looks at his watch, on his left hand, it says 8:10, and has a black dial/face. As Dean and Bobby go through the rubble, Dean identifies Ash by his watch. Still on his left hand, it is now upside down, evident by the crown of the watch (used to move the hands of the watch) which previously facing his hand, is now facing his elbow. Also, the dial/face of the watch is now silver instead of black. This is a different watch, and was inadvertently put on the burnt arm upside down.
Continuity mistake: When Dean reads about the Roosevelt Asylum in his dad's journal, there is a picture of a Wendigo on the opposite page of the newspaper clipping but in a different scene, Dean checks the article again for information on the South Wing in the Asylum but this time on the opposite page of the newspaper clipping, there is no picture.
Continuity mistake: Near the end of the episode when Dean is being chased by the possessed truck, Sam tells him to take a left. After he's made the left, Sam tells him to go exactly 7/10ths of a mile and stop. Dean looks at his gage and it reads 70098.3. Dean looks up, then back at it: it changes to 70098.5, but the next time he looks down it says 70100.6 and when he stops it says 70101.0, meaning he's gone 2 miles too far. (Probably meaning it took two shots to get the scene right but they messed up on the gage.)
Continuity mistake: In the scene where Dean is with Bobby at the burned down Roadhouse and Dean gets Andy's vision about where Sam is, the first time Dean scrunches his face in pain he puts his left hand to his head. The shot changes to a back view and you can tell his left hand is still at his head. But when the shot switches again Dean is bringing his right hand down from his head.
Continuity mistake: When Sam and Dean enter the Shoemaker home, a woman leaning against a wall holding a coffee cup starts to follow them down the hall. When the shot changes, the woman is back against the wall, talking to someone who wasn't there in the previous shot.