Witchstock - S6-E11
Plot hole: This episode takes place in 1967, and Penny (Grams) is married to a man named Allen Halliwell who dies in the episode. Allen is supposed to be Penny's "first husband," Patty's father and the Charmed Ones' grandfather. But it was previously established that Patty's father was named Jack, and he died in 1964. Also they hint that Patty is still little but we know she was born in 1950 so she would be 17.
Witchstock - S6-E11
Continuity mistake: Robin falls over backwards after Paige dumps a cannister of marbles onto the floor. But Robin wasn't moving at all when this happened. Trying to walk over marbles will make you fall. Standing still while marbles roll around and bounce off your feet? Not so much.
Witchstock - S6-E11
Character mistake: Phoebe, who has moved to Hong Kong, tells Paige that she, Paige, was born in the Year of the Ox. But Paige was born in 1977, the Year of the Snake. 1973 was the Year of the Ox.
Witchstock - S6-E11
Plot hole: After Paige changes the past, the ghost of Grams changes from a no-nonsense demon-hunter into a pacifist hippie. So, apparently, we are now in an alternate timeline where Grams never became assertive, and stayed a hippie all her life. The episode went to great lengths to establish that if Grams had stayed a hippie, she and the Charmed Ones would have all died young. But the ghost of Grams was still middle-aged, instead of decades younger, and Wyatt and Chris were still there, but they wouldn't have been if their mother Piper had died as a child.
Visible crew/equipment: In the scene with Chris and David in the attic, a boom mic dips into the shot. (00:28:50)
Continuity mistake: When Piper, Paige and Phoebe are having a food fight, Piper freezes the cake, then she throws it at Paige who suddenly has a mysterious stain on her top. Then Piper has orange food on her hands even though she hasn't touched anything orange, and the stain on Paige's top has gone.
Other mistake: During the second attack on Wyatt, when he lets his force field down the top of head is transparent from the special effects.
Used Karma - S6-E13
Continuity mistake: In the scene when Piper is fighting off demons by herself at the start of the episode and Phoebe and Paige come to help her, she narrowly misses a fireball and jumps down to the ground to dodge it. In the shot before, her forehead is un-injured, but as she dives to the ground you see that she is already bleeding from her forehead, *before* she actually hurts it. (00:02:30)
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)
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.
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 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
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)
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
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.
Continuity mistake: Near the beginning when Chris and Phoebe are talking in her office, the loose ends of her scarf switch from being in front of her to being over the back of her shoulders in almost every shot. (00:00:50)
Continuity mistake: When Chris tells Phoebe that searching for Jinny at the dig site may be a trap Chris is wearing a zipper hoodie, but in the next overhead shot just as Chris sees the hole containing bones Chris has on what looks like a leather jacket, and then it's back to the zip hoodie. This is odd, because it's not until later after Leo heals Chris, that we even see Chris in the leather jacket. (00:03:10)
Factual error: When Leo shows Piper, Phoebe, and Chris the "warning label" on the genie bottle, he turns the bottle clockwise, reading from left to right. Arabic is read from right to left.
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)
The Courtship of Wyatt's Father - S6-E16
Continuity mistake: When Leo and the sisters are in the alley with darklighters, Phoebe falls from the roof and her high-heeled boots become flat shoes. (00:14:40)
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.