Nina: I'll tell you where the bomb is in exchange for immunity.
Novick: The President's already granted you a total pardon.
Nina: Except this is a crime I haven't committed yet.
Novick: What crime?
Nina: The murder of Jack Bauer.
Kiefer Sutherland injured his leg while leaving his trailor. The writers had him pull a piece of wood from his leg after the plane crash so they could explain the limp. The limp disappears after this episode.
When Michelle tells Tony about a co-worker telling her that he saw Mason throwing up in the bathroom, she is referring to a deleted scene (originally scheduled to be the opening segment) that featured Mason doing just that.