When a panicked Meredith first runs into her apartment after a terrifying chase by an imposing shadow, she quickly disarms her security system which is oddly attached to the left side of the door itself and not mounted on the wall, latches the chain lock which is also to the left side of the door, re-arms the alarm, then swiftly becomes nonchalant as she opens a beer and casually listens to the messages on her answering machine. Later when Sam & Dean arrive, the landlord opens her apartment door for them and now the door opens from the opposite side, the alarm is mounted on the wall and not the door.
In Zoroastrianism Daeva means "wrong god" or "false god" not "demon of darkness".