गूफ़

Near the end of the movie, in the morgue, Stephanie and Sam are sitting on the floor, with a wall behind them. Constance throws the syringe in their direction. Then, we see the syringe in the wall, close to the right side of Sam's head. Few moments after, when both are going to stand up, the syringe has disappeared. (Maybe they are sitting a little farther than previously).