Wicca Envy - S1-E10
Continuity mistake: At the beginning of the episode when Piper hides her sisters from Leo she has the shirt with the buttons closed, but between that scene the shirt is not closed. (00:01:05)
Continuity mistake: When the sisters first see the lady in the lake, the demon off to the side throws a knife into her back, but the knife hits completely straight, as it would if the demon had been directly behind her.
Continuity mistake: When the main Calloway throws the clear bottle with the green potion at one of the enemies, the shot cuts and it's now become a white bottle.
Continuity mistake: Right after the Hawker demon attacks, Piper picks the baby up and the head of the doll is covered and you can't see the face; a quick change in camera angles shows the baby's face and the blankets are all arranged and folded to frame the baby and no time has elapsed to allow this to happen. Also, the doll used as the baby double is much smaller than the baby and is very noticeable in shots that switch back and forth between the covered doll and real baby.
Continuity mistake: In the scene with Paige and Jordan Bridges' character, nearer the end, when they are sitting on the couch and his possessed character leans in for a kiss, from the back shot, he leans in and his head is tilting towards his right shoulder (you see part of his profile and the back of his head and Paige's face); when they change the shot so you see the front of his face and the back of Paige's head, his head is tilted back towards his left shoulder.
Is There a Woogy in the House? - S1-E15
Continuity mistake: At the beginning and throughout most of the episode you can see the entrance to the basement. If you look to the right of the door you can see a light switch by the door with the cover on it. At the end of the episode they show the entrance but this time the cover to the light switch is off.
Continuity mistake: When Phoebe is talking to Elise on the phone, the phone handset jumps from Phoebe's left hand to her right hand, then back to her left. (00:20:40)
Continuity mistake: When Piper is grieving Prue's death in the mausoleum, Leo's hand moves from cupping her face to resting on her shoulder blade between shots. (00:37:15)
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)
Continuity mistake: When Phoebe is attacked by Anton's spirit, she puts her right hand over her throat twice. (00:03:15)
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)
We're Off to See the Wizard - S4-E19
Continuity mistake: When Leo arrives to tell the sisters about the wizard, Phoebe's hands change position between shots. (00:29:55)
Continuity mistake: When Prue, Phoebe, and Leo enter the kitchen to find Piper covered in watermelon, the amount of fruit on Piper changes in the next shot. Her hands also change from being supine to prone. (00:19:00)
Continuity mistake: When Piper accidentally blows up the teapot, she has her hands up by her chest, in Prue's, but in the next shot her arms are down by her sides. (00:19:55)
Charrrmed! - S7-E4
Continuity mistake: When Piper watches Leo sleeping with Wyatt and Chris, the book on Leo's chest disappears and then reappears. (00:38:45 - 00:39:15)
Charrrmed! - S7-E4
Continuity mistake: When Black Jack Cutting's parrot delivers the invitation to Piper and Phoebe, it drops the invitation on the window sill. When Leo goes to pick the letter up, it moves closer to him than it was before (in particular, watch it relative to the parrot's left foot). (00:29:40)
Continuity mistake: In the opening scene in the club with the DJ playing, they have an overhead shot of the club. In the lower right hand corner we see Paige and Dave talking with Leo and Piper, but after the scene cuts out Piper is just walking in. This can't be since we already saw them talking.
Used Karma - S6-E13
Continuity mistake: In the scene when Paige and Piper are doing first aid on each other, Piper makes quite a production out of the business of peeling the backs off band aids to apply to Paige's arm - but when she slaps it on Paige's arm, it's a non-adhesive white 4 x 4, which Paige has to hold on her arm with her other hand.
Used Karma - S6-E13
Continuity mistake: At the beginning, Piper is wounded on her forehead by the demons. When they orb out and orb into the kitchen Piper doesn't have a wound on her head anymore. (00:03:25 - 00:05:40)
Continuity mistake: When Matthew starts crying and Piper freezes him, Prue puts her hands on her forehead. In the following close up, her hands are brushing her hair back, then back on her forehead in the next wide shot. (00:23:00)
Answer: That was a mistake in the series.
Also, the episode is called 'Babies First Demon' and this alone tells us that it's Wyatt's first time in the field (so to speak) and as the sisters say, they've done a good job of clearing up their own magical messes so far. Nobody really knows how advanced Wyatt's powers are, or will become. That's why the cleaners appear, to nip things in the bud. The Cleaners didn't want to chance that the sisters could clean Wyatt's magic up, just incase they couldn't. Therefore intervening themselves, just in case.