Continuity mistake: After the ghost chases Gibbs out of his pawn shop, and the police arrest him, his shirt goes from being on fully to half-off between shots (particularly noticeable when Tyra's father tells him to burn in hell).
Revealing mistake: The sheet-covered body of Charlene that is being moved by the police has obviously got a head, despite the fact that she was meant to have been decapitated.
Revealing mistake: When the pawn shop owner jumps through the glass door, it is painfully obvious that it's a stunt double.
Chosen answer: Her agent/manager negotiated a special billing as part of her contract. It distinguishes her from the rest of the cast, probably when she became a producer on the show.
JC Fernandez