Revealing mistake: When Paige cuts the flesh away from Sykes, you can visibly see a white bandage-like thing under his skin as it comes off. (00:23:20)
Revealing mistake: In the beginning of the episode, Yenlo and Anling are fighting with swords. After Yenlo says, "I'm going to kill him, Anling. And then I'm going to kill you," Anling stabs him with her sword. Yenlos' wound is very bloody, but there is no blood on Anling's sword at all. (00:04:25)
Charmed and Dangerous - S4-E13
Revealing mistake: During the episode, Paige is wearing a sleeveless top, but when she thrown across the attic by 'The Source' the stunt double is wearing sleeves. (00:37:45)
Continuity mistake: If Leo can't hear the girls call him when HE is underground, he shouldn't be able to hear the girl's call him when THEY are underground and he doesn't know they are at P3 until a few minutes later.
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.
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.
Continuity mistake: Near the end of the episode, in the scene at P3, Phoebe launched a jump kick at a warlock after Paige has been knocked down by a small energy ball. Everybody else in the club was frozen by Piper, but when Phoebe lands she jostles a blonde extra who moves from her pose.
Continuity mistake: After Phoebe and Paige have switched bodies and Phoebe is trying to teach Paige how to levitate, Phoebe's hair switches from her shoulder to her back then to her shoulder again. (00:20:15)
Continuity mistake: When Paige was invisible and Cole watched the blood, there was a large pool of her blood, but in the next shot, the pool of blood was smaller. (00:36:00)
Continuity mistake: In the scene where Agent Jackman shows them the file he has on them in their dining room, Paige's left dress strap has fallen off her shoulder in some shots, but in others it's perfectly in place.
Continuity mistake: In the teaser, Phoebe has a vision of a murder. When she first sees the shadow of the attack, the assailant is holding his victim down with his right hand while stabbing with his left. Then when the vision focuses on the Medusa head tattoo on his forearm, it is the right arm that is stabbing. (00:04:15)
Other mistake: The one demon that knew about the 40s party was vanquished, and he went straight from spying on Paige and Phoebe at P3 to "glamouring" into Leo at the Manor. He had no way of telling Devlin about the 40s party, and yet it was still full of demons waiting to kill the Charmed Ones, with Devlin "glamoured" into Melody as a trap. And Devlin didn't even have that power - the demon that was vanquished did.
Plot hole: After Cole explains he might not be able to regain control after embracing his demonic half, he tells Phoebe she should have the Belthazor vanquish potion ready just in case. But in "Look Who's Barking", Piper tried using that potion on Cole and it didn't work because he had himself magically protected from it. (00:27:15)
Charmed and Dangerous - S4-E13
Other mistake: In this episode, the Source talks about the "Ultimate Power" being the Hollow. But in Season 8, we learn that the "Ultimate Power" is Billy and Christy. (And they end up taking in the Hollow, so now are they the "Ultime Power" times 2?) Which is it? It can't be both. (00:02:05)
Charmed and Dangerous - S4-E13
Revealing mistake: At the end of the episode after Phoebe and the Seer put the hollow away in its place, she leaves, but when it next cuts to a closeup of Cole, in the corner of the screen you can see her hair. (00:41:50)
Continuity mistake: After the "dirtbag" is brought back to the manor and Piper is ragging on him, Piper gets very angry and decides to blow her husband up. Less than a minute later, Cole says "Back away slowly, Leo." Leo says "What?" and Cole says "She's becoming a fury." Then it shows Pipers hands, which now have long black fingernails, but they just suddenly show themselves right when Cole decides to show up and say she's becoming a Fury. When she blew Leo into orbs there were no long black nails. (00:25:35)
Continuity mistake: In the church scene when Phoebe and Piper are showing Paige how to use her power, Piper says "according to the prophecy, the third sister has the power to move things with her mind, like Prue could." Prue was not the third sister, but the first. Paige is technically The Fourth Sister, but since the prophecy didn't speak of a "Power of Four", she would automatically become the third sister after Prue's death. (01:02:42)
Continuity mistake: During the opening, Piper, Phoebe and Cole are in an SUV and going to find a demon. A shot from in front shows that there is no rearview mirror in the SUV, just a white mark on the windshield. When they turn into the parking lot however, the rearview mirror has returned.
Other mistake: This entire episode the ghost brothers whine that Leo is responsible for them dying and he left them to die, even Leo believes this. It makes no sense. As we see in the flashback even if Leo stayed to help they were blown up moments later and still would have died.
The Three Faces of Phoebe - S4-E14
Continuity mistake: When Phoebe casts the spell to hear her hearts desire about marrying Cole it conjures old Phoebe and young Phoebe. When Leo, Piper, and Paige enter the room they all room perplexed by who the two people, just conjured, are. If this is supposed to be young Phoebe, wouldn't Leo (who has followed all them their whole lives) Piper and especially Phoebe recognize the younger Phoebe immediately instead of being confused by who she is?
Answer: "Hush, Hush, Hush" Paula Cole.