Plot hole: When the Avatars agree to rewind time they say that they can either put the world right or save Brody but not both. This doesn't make sense since they're rewinding to right when they put everyone to sleep, which is before Brody was killed.
Other mistake: When Phoebe gets the premonition to see all the loss, she sees the scene where Piper dies in All Hell Breaks Loose. Since time was rewound this event never happened in this timeline, and we're never given any reason to believe Phoebe would know this happened after the time reversal.
Other mistake: After they talk to the Angel of Destiny for the first time, they send Leo to ask the Elders if he is legit. After Leo leaves they find out about Agent Jackman, and the following events unfold. After Jackman busts them Piper calls for Leo and tells him "It's OK, you can orb" and he appears asking her "What about Agent Jackman?" Except that Leo was gone before they found out about him and the girls hadn't told Leo yet that he even existed. (00:09:09 - 00:21:58)
Other mistake: When Phoebe is trying to summon Angela the spell doesn't work and Leo says that she needs the power of three. We've seen this spell done with just one sister in the past and it's never explained why they'd need to do it together this time.
Continuity mistake: Whilst Paige and Phoebe are jumping through time, they witness Piper telling Leo she loves him for the first time. After she tells him, Leo orbs Piper and himself away. This doesn't make sense as the first time Leo orbs Piper is in season 2 Episode 8 - the water demon episode - which is actually further on in time from when she tells him she loves him (which is from season 1 episode 21).
Valhalley of the Dolls (1) - S6-E1
Plot hole: Phoebe becomes an empath. But in Primrose Empath (S3:E6) Leo tells the sisters an empath is a mortal who has died and come back as an empath, so it wouldn't be a progression of a witch's powers like it is in this episode. Plus Phoebe isn't dead.
Suggested correction: There is a difference between an Empath and the power of Empathy. A true Empath is a mortal that has died and been reincarnated and they are a separate race of magical beings. But other beings, such as witches, can have the power of empathy. It does get confusing because they refer to a witch with empathy as an empath, but that doesn't mean they are true empaths. In addition, Phoebe developed her empathy powers in her 20's as one of her first powers and her power of empathy is the strongest of any being.
And where is this stated anywhere in the 8 seasons of the show?
Plot hole: Paige is able to use the enchantress' powers, but in "Pardon My Past", Phoebe can't use her past life's fire throwing power and Leo tells her it's because her past life misused it so she lost it. The enchantress misused her powers so Paige should not be able to use them.
Plot hole: The demon is killed when Leo proposes, hence before the wedding. So how is he able to break the cake topper?
Be Careful What You Witch For - S2-E22
Other mistake: Phoebe says to the genie "you've been stuck in the bottle for 200 years?" Later the genie says he will be an unwelcome house guest and not put the CD's back in their case. If he was in the bottle for 200 years how would he know of CD's?
Continuity mistake: The furniture used throughout the show regularly gets blown up or destroyed but then mysteriously re appears later on or in the next episode.
A Wrong Day's Journey Into Right - S6-E20
Revealing mistake: Right after Paige is orbing out, the camera is on Phoebe and on her right, you still see Paige's shoulder. And then it cuts to Paige orbing back in.
Factual error: During the ritual, we can see that the snake that is magically transformed into a man is a milk snake. But it's not poisonous, it's a colubrid. The creators apparently wanted to use its resemblance to a poisonous coral snake, which is an elapid. (00:02:35)
Continuity mistake: When Paige is at the bar with her newest charge we see the same extra walk by 3 times, going the same direction each time.
I've Got You Under My Skin - S1-E2
Revealing mistake: At the end of the episode when Phoebe and the other two are at the bar you can notice that Prue straw in her drink goes in and out of her drink a great deal.
Continuity mistake: When Prue lets Matthew out of the locket, the front view Prue has her right hand on her stomach, when the shot changes to the back view her hands are by her side, it does this multiple times.
Something Wicca This Way Goes - S7-E22
Continuity mistake: When Zankou is looking at the spell in the Book to steal TCO powers we see that it is the same spell Aunt Gail used in "How to Make a Quilt out of Americans", except that in that episode she ripped the page out of the book. It shouldn't be there for Zankou to use. (00:09:56)
Visible crew/equipment: When Piper is coming down the stairs with the staff, if you look in the top left corner of the stairs, you can see a piece of camera equipment moving.
Love Hurts - S1-E21
Continuity mistake: Leo dies and then Piper heals him. In all future episodes it's made very clear that Leo's powers can't heal the dead.
Charrrmed! - S7-E4
Continuity mistake: Baby Chris doesn't have a binkie in his mouth, then does, then doesn't. (00:39:23)