The Legend of Sleepy Halliwell - S6-E14
Other mistake: In previous episodes it is stated that good witches don't freeze. But after Piper has been decapitated and her head is placed in the manor, one of the students freezes all the kids by tapping into Piper's freezing power. The kids are all good witches so they should not have frozen.
The Legend of Sleepy Halliwell - S6-E14
Continuity mistake: When the shaman offers Phoebe the vision quest potion, she alternates back and forth from holding the cup with both hands to one hand. (00:20:15)
The Legend of Sleepy Halliwell - S6-E14
Other mistake: When Phoebe arrives back from her vision quest to find Piper has been kidnapped she tries to sense from the frozen students which one created the headless horseman. As Gideon, Paige, Chris and Phoebe walk into the conservatory you see Zachery blink rather obviously.
The Legend of Sleepy Halliwell - S6-E14
Visible crew/equipment: When Leo and the sisters enter the great hall we hear Gideon call to Leo and thank him for coming, then as the camera pans to the left we can see the T-mark on the floor, at the bottom left corner of the screen. (00:09:25)
The Legend of Sleepy Halliwell - S6-E14
Continuity mistake: When Phoebe comes out of her vision quest the third time, the shaman holds out the potion cup by the handle, but in the next shot, she's holding it by the bowl. The cup also appears to jump from her right hand to her left. (00:30:35)
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