The Cabin in the Woods (2012)

Continuity mistake: Before Dana and Marty enter the control room and release all the monsters into the control centre, there is a thermos flask and a torch sitting next to each other on the control room's desk. But once they enter the control room, the position of the thermos flask and torch have changed without anyone touching them.

THGhost

The Director: This is all most unpleasant. I know you can hear me. I hope you'll listen. You won't get out of this complex alive. What I want you to try to understand is that you mustn't. Your deaths will avert countless others. You've seen horrible things: an army of nightmare creatures. And they are real. But they are nothing compared to what lies beneath us. There is a greater good, and for that you must be sacrificed. Forgive us... And let us end it quickly.

Trivia: The movie pays tribute to many famous horror movie monsters. The creature with the Buzz-Saws in its head with the Puzzle Orb is based off PinHead. Once it's free, you can see a Chatterbox-influenced cenobyte standing next to it. The people with ceramic masks who tie up and torture the scientists are based off The Strangers. The psychotic clown with the knife can either be seen as a tribute to PennyWise or Killer Clowns from Other Space. The massive killer bat is obviously from the movie BATS. A chainsaw can be heard as the different monitors are showing the slaughter - indicating LeatherFace. The ghoul-doctors operating on a victim while staring into the camera is based off House on Haunted Hill. The Red-Neck zombies brought to life through an incantation from a book is a tribute from The Evil Dead. The Scare-Crow-like zombies who kill the black security guard are based off of the movie ScareCrow.

Question: How did the demolition woman who is shown on a monitor shooting herself get the gun in the first place? After all, she isn't a security guard.