Continuity mistake: When Piper confronts Phoebe about casting the spell to help her decide between Dan and Leo, Phoebe's finger jumps to the back of her ear, then disappears. In a following shot, her finger is now resting on her neck. (00:09:45)
Continuity mistake: When Prue shows her sisters the article in 415 Magazine with her photo credit, in the closeup we see that Prue opens the magazine with the article and Maggie's photograph on the page to the right, but in the next shot facing Piper and Phoebe the magazine is folded open and they're looking at the page to the left with an entirely different page to the right. (00:40:40)
Continuity mistake: In the shot where Leo gets his wings back, his eyes are brown, usually they are blue.
Revealing mistake: When Maggie Murphy climbs onto the ledge of the roof to jump off you can see the surface of the ledge dipping as if it was foam.
Chick Flick - S2-E18
Continuity mistake: After Phoebe kisses Billy, she sees that the makeup over his lips has washed off and that they're in black and white again. While she applies more to him, the phone rings, Billy turns his head, and his lips are normal. In the next shot, they're back to being in black and white. (00:22:15)
Chick Flick - S2-E18
Continuity mistake: In the teaser, Phoebe took off her messenger bag while she was sitting in the chair talking to Prue, and she left it there when she went up to get the door. For the rest of the scene at the house, including when Phoebe and Prue ran out of the door, Phoebe was not wearing the bag. Then, when we saw them outside immediately thereafter, Phoebe was wearing the bag again.
Chick Flick - S2-E18
Character mistake: After the horror movie characters were killed in the attic, the sisters hear the door bell ringing. When they get to the bottom of the stairs and start walking towards the front door, you can see the actor playing Billy smiling even though they're all supposed to be on edge.
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.
Visible crew/equipment: When the sisters hide the chimps in the laundry cart to slip out of the hospital, the blue T-mark is visible on the floor at the bottom of the screen, before they peek around the corner and notice the TV. (00:20:15)
Continuity mistake: Near the end of the episode Piper is talking to her sisters in the parlor with her watch is on her left wrist and a bracelet on her right wrist. She goes upstairs to her room to cry and her bracelet and watch have switched places. (00:39:05 - 00:40:00)
Revealing mistake: When Phoebe punches Dr. Williamson, it's easy to tell that she doesn't really punch him.
Be Careful What You Witch For - S2-E22
Visible crew/equipment: While Leo is up in the attic with Piper, flying Phoebe, and teenage Prue, Leo explains what happened to Prue, and when Phoebe asks how it's even possible, we can see the stunt harness at the back of Phoebe's jeans as she rises in the air. (00:18:45)
Be Careful What You Witch For - S2-E22
Revealing mistake: During the search for the Dragon and teenage Prue, Phoebe's wearing a red top and red jacket, but when Phoebe lands on the ground we can see the bulky beige material of the stunt vest at her back, under the red top and jacket. (00:34:05)
Be Careful What You Witch For - S2-E22
Plot hole: When teenage Prue has run away with the demon, and Phoebe and Piper find her in the park, teenage Prue is 'killed'. Her sisters drive her home to get Leo to heal her, but shouldn't they have just been able to call to Leo to orb to them when Prue was first hurt, and heal her in the park, and save driving back to the Manor, risking Prue dying?
Suggested correction: I see orbing to the park but he didn't heal her, she was already dead and he can't heal the dead, that's why the genie brought her back - that's what Phoebe wished for.
But if they would have called for him right away - he would have been able to heal her before she died. However at this point in time I don't think they knew how to call for him.
Be Careful What You Witch For - S2-E22
Continuity mistake: When Piper and Leo confront the genie at the restaurant, the genie is eating food as fast as he can. At one point he gets a line of pasta sauce on his cheek. The shot changes, then goes right back to him only now the sauce is gone with no time for him to have wiped it off, especially since his hands are full of food.
Be Careful What You Witch For - S2-E22
Continuity mistake: When Phoebe and Piper are leaving to go get Prue, Piper kisses Leo on the cheek and there is a lipstick mark on his cheek. Then the shot goes to Piper then back to Leo, and the mark has gone with no time for him to remove it.