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.
Plot hole: When Sam and Dean realise they need to destroy the hook to stop the Hook Man, they find out that it has been reforged into something else. They state it needs to be set on fire to stop him, but if it was melted down and reforged then it has already been set on fire and the Hook Man shouldn't be latched on to it in the first place.
Continuity mistake: The baby gets into the fridge, which then closes - we see a closeup shot of the babyproofing clip shutting itself. Then when the mother sees the spilled milk and realises what's happened, there are a few shots of the fridge - in shots from the front the clip's open, and in shots from the side it's closed. When she goes to open the fridge it's open again - she even fiddles with it to give the appearance of undoing it before opening the fridge door.
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.) (00:35:00)
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. (00:08:00)
Visible crew/equipment: When Sam tells the little girl to take her brother outside. The little girl runs out with her brother and Dean asks the little girl where Sam is, Dean runs to the Impala and grabs a shotgun. When Dean is running to the house, he runs on the lawn and you can see the shadow of the camera man running with Dean at the bottom of the screen.
Continuity mistake: During the scene where Sam is tied up and eventually fights the fake-Dean in Becka's house, there is a shot that shows both his feet and hands tied. During the fight, both his hands and feet are shown free, but he only cut free his hands, and began fighting immediately after that. (00:25:20 - 00:25:55)
Other mistake: In the scene where Sam, Dean and Sarah go to compare the painting to the earlier photo of it, Dean, noticing the changed position of the razor, says, "Jared, check it out." He is speaking to the character Sam. The actor's name is Jared. [Confirmed in cast interviews].
Continuity mistake: Both Sam and Dean show no signs of bodily damage or harm, even though in the previous episode "Shadow," both brothers were attacked and their faces had been slashed by the shadow demons summoned by Meg.