At the end after Dean leaves Tara's trailer and he and Sam walk away, Tara is standing in the doorway and goes back into the trailer. In the next shot, she is still standing in the doorway.
While Sam and Dean are on the studio tour, Dean states that the movie Creepshow (1982) was filmed there. Actually, Creepshow was filmed primarily in and around Pittsburgh, PA and the surrounding area (with some scenes filmed in New Jersey.)
When Sam fast-reverses the daily DVD to listen to the invocation, what is shown on screen looks more like rewinding a MiniDV tape than fast-reversing a DVD (pixelation as opposed to a series of still images). Pixelation as shown wouldn't happen when fast-reversing a DVD.
When Dean is shown with a headset for the first time (18:10), it looks like the other end of the headset wire isn't attached to anything. However, what is actually visible is the clip used to hold the cable to your clothes; because Dean is not using the clip, the cable dangles and appears to be free (although it isn't).
It wouldn't have actually been possible for the guy to get sucked into the giant fan and killed by it because of the metal cage surrounding the blades, a safety feature to prevent exactly that kind of mishap with blade fans.