Thank You for Not Morphing - S1-E3
Factual error: At the end of the episode the girls are waiting for Victor. He doesn't show up but sends a package containing a home movie. As they are watching it, they see Christmas when they are little girls. Phoebe can't be more than 4 yrs old, 5 at the most. Since she was born in 1975 that would make the home movie take place in approx 1980, but she gets a Wedding Day Barbie, which didn't come out until 1996.
All Hell Breaks Loose - S3-E22
Continuity mistake: When they first bring the doctor to the manor the sisters tell him they're not sure who's trying to kill him, then a few minutes later Prue tells him exactly whose trying to kill him, Shax, the Source's assassin.
Crimes and Witch-Demeanors - S6-E19
Audio problem: When Chris accidentally drops Phinks into the lava pit in Hell, he says "shoot", but his mouth is saying "shit." (00:21:10)
Plot hole: When Phoebe and Paige are be sent through Piper and Leo's past we see things that that cannot be true. 1. When Leo was dying in "Love Hurts" you see Piper and Leo orbing, but in the actual episode they walked down the stairs. 2. In "Just Harried" we see the cake fall and the Statue skid on the floor, but in the actual episode it was caught under the cake.
Continuity mistake: In the shot where Leo gets his wings back, his eyes are brown, usually they are blue.
Audio problem: Baby Matthew is supposed to be screaming his head off, when Prue levitated the contents of her purse to cheer him up. But she turns him to the camera and he is smiling. (00:21:40)
Continuity mistake: In this episode, an invitation to Piper is addressed to 1329 Prescott Street. But in episode 1-7: "The Fourth Sister," the Halliwell sisters put up a flyer for their lost cat, and it gives their address as 7571 Prescott Street.
Continuity mistake: In the scene where Phoebe dangles the slumlord from the roof, the TransAmerica Pyramid can be seen behind Phoebe and Cole. A subsequent shot, after Phoebe tosses the slumlord back onto the roof, is take from the opposite side, but the TransAmerica Pyramid is still behind them, and is much closer. (00:25:25)
The Courtship of Wyatt's Father - S6-E16
Continuity mistake: When Gideon warns Sara not to use magic to put the books in the library back on the shelves, her arms are at her sides. A second later, the shot changes to over her shoulder as Leo orbs in and she has a nearly full armload of books. (00:08:55)
Plot hole: Paige says she cannot wait to tell the local witch doctors that Borneo demons are not impervious to magical powers. But in the episode 'House Call', they act as if they have never heard of witch doctors, let alone dealt with them. (00:01:45)
Continuity mistake: When Leo and Ramus are talking in front of the bay windows, the door behind Ramus switches from closed in the wide shots to open in the close-ups. (00:31:50 - 00:33:00)
Power Outage - S3-E7
Revealing mistake: Alyssa's tattoo is visible when Phoebe leaves Cole's apartment after she fought with her sisters.
Coyote Piper - S3-E9
Other mistake: At the beginning of this episode, Tara and Kierken are arguing and Kierken says that he could always "suck you into your little mixing bottle and start again." Then Tara says that "she has a better idea," and then she stabs herself. The life essence automatically flows out of her but the knife was still in her body. Later, the possessed business man stabs himself in front of Piper and she kneels down to see if he was okay and the essence flew into her, without the knife being removed from his body. At the end, when Leo comes down after Prue stabs the possessed Piper, he kneels over her, but the essence does not flow into him. It only flows into him after he takes the knife out of her body.
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)
Something Wicca This Way Goes - S7-E22
Continuity mistake: Phoebe's shoes change between shots. Near the end, while fighting Zankou in the basement, he hurls the sisters to the ground and Phoebe is shown wearing sandals. When she stands up, she is now wearing sneakers.
Siren Song - S5-E4
Continuity mistake: When Piper and Paige fall out the window and land in the dumpster, in the wide shot the garbage bags are white, and in the close-up they're blue. (00:16:45)
Continuity mistake: At the beginning of the show when Piper comes into the kitchen to help Paige, she is wearing slippers. In the next shot, when she is by Wyatt's chair, she is wearing flip flops.
Continuity mistake: When Cole gives Phoebe his card on the school campus, it disappears and reappears between shots. (00:23:25)
Revealing mistake: When the prince is supposed to be frozen on Paige's living room couch, when they do a close-up you can see the actor blink.
Is There a Woogy in the House? - S1-E15
Continuity mistake: At the beginning of the final scene in the attic, the view from the window prominently features the Transamerica Pyramid. At the end of the scene, the view is completely different, showing the Ferry Building and the Bay Bridge. (00:41:30)
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.