Visible crew/equipment: In the scene before Dean makes the promise to Sam, as the camera pans along the side of the Impala, in the rear of the car, you can see the dolly track that the camera runs along.
All Hell Breaks Loose: Part 1 - S2-E21
Visible crew/equipment: When dean and Bobby drive to the burnt down road house, you can see the boards holding up the wall in the set at the old front door, the boards are set at a right angle to hold the wall up but definitely wouldn't be there it the place was intact.
Answer: Over the next few episodes, it is revealed that something is not quite right with Sam - that his soul is missing since he returned from Hell, and he does not feel any emotion or attachment to his brother.
Sierra1 ★