When Jack is in the food locker the voice he hears coming from behind the door, identifying itself as Grady, sounds nothing like Grady did when the two were conversing in the Gold Room. This is a film about dual natures and Grady's first name is changed from Charles to Delbert in the course of the film. He is Delbert Grady in the Gold Room and only Grady when he is behind the door. I believe he is now Charles Grady when he is speaking to Jack from behind the locker door. I know he refers to the matter they previously discussed but again dualities!