Changes

* In [[4.16 On the Head of a Pin]] it is never explained how Anna regained her destroyed human body. Also in the episode Alastair was shown to be affected by contact with holy water, however in [[1.22 Devil's Trap]], Azazel, a demon lower on the hierarchy was shown to be resistant to holy water.

* In [[5.03 Free to Be You and Me]] Castiel states that an angel cannot touch or pass through holy fire, or it will die. In [[5.22 Swan Song]] [[Michael]] is able to survive being engulfed with holy fire.

* In [[5.10 Abandon All Hope...]] it is never explained how Lucifer knows about the Colt, as he would have been locked away in the Cage when it was created by [[Samuel Colt]]. And even if he was told about the Colt after being released, he would not be aware that he is one of the five things in all existence it can't kill.

* In [[6.04 Weekend at Bobby's]], it is revealed that a [[demon]] can be destroyed by burning its earthly remains. However, John Winchester's spirit is shown escaping from [[Hell]] in episode [[2.22 All Hell Breaks Loose: Part Two]] despite his remains being burnt at the beginning of [[2.02 Everybody Loves a Clown]]. One possible explanation for this discrepancy is that burning a demon or spirit's remains only destroys it if it is on Earth (in the case of a demon, possessing a human on Earth). It is also plausible that John was never a demon, considering it is said that he did not break the first seal while in Hell, and thus he did not start the Apocalypse. It was Dean who ended up being the righteous man to start it.