The Demon Who Came In from the Cold - S3-E19
Visible crew/equipment: After Prue removes the piece of Belthazor flesh from the freezer it cuts to Cole finding Phoebe's note in his pocket with a closeup of Cole, and at the start of the next shot the reflection of the boom operator holding up the boom pole and mic can be seen on the glass window, behind Pirelli/Vornac. (00:28:05)
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