Which Prue Is It, Anyway? - S1-E16
Continuity mistake: While Phoebe explains the slam man training system Piper puts on Phoebe's boxing gloves, and when Prue says that demons don't play fair Piper playfully raises her left arm to Prue's forehead, but in the next shot facing Prue it's Piper's right arm that's raised. (00:04:00)
Which Prue Is It, Anyway? - S1-E16
Continuity mistake: When Prue goes up to cast the spell, Piper and Phoebe are downstairs and Piper's hair is down. When they hear the effects of the spell they run in to the attic and both say "Oh my god!" one after the other and Piper's hair is now slicked back in a ponytail.
Which Prue Is It, Anyway? - S1-E16
Revealing mistake: When Pink Prue is stabbed, they show the warlord over her, with the sword supposedly having stabbed her body. It is very obvious that the sword is not actually in her, but about a foot away from her body, closer to the warlord.
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