Plot hole: In episode 1-2 ("I've Got You Under My Skin"), Alec buys Phoebe a martini at Quake. but then in episode 5-11 ("The Importance of Being Phoebe"), Cole tells Kaya that Phoebe doesn't drink. Then, in episode 5-17 ("Lucky Charmed"), Jason buys Phoebe a "Martini, dirty" at the end.
Necromancing the Stone - S5-E21
Plot hole: Piper mentions that Grams banished the Necromancer "sixty years ago" at Patty's Wiccanning. Grams soon thereafter says that the Necromancer has had "almost seventy years" to regain his strength. However, Patty was born in 1950, and this episode aired on 5/4/03, at which time Patty's Wiccanning could not have been more than 53 years earlier.
Plot hole: In 'Centennial Charmed' Paige orbs to another reality where she loses all her powers. Leo tells her the this is because she was never called as a witch in this world, but Paige had most of her powers before she was called because of her whitelighter blood, so she should retain these. Leo says that Paige has assumed the life of this reality's Paige, but then adds "...or at least the life she would have lived if she hadn't been killed". If alternate Paige had lived she would have had Whitelighter powers, even if she didn't know about them, so our Paige should also have them. (00:28:00)
Plot hole: The Sea Hag says at the start of the episode to Mylie that as an immortal being, only she can place the augur shell over her heart to give up her life. But at the end of the episode Necron magically places the shell onto Phoebe and it nearly sucks the life out of her. (00:03:20 - 01:14:55)
Plot hole: In this episode, when Piper and Leo are preparing the nursery, Leo tells Piper he has been watching her her whole life, and she says "That's a little bit creepy". she acts as if she doesn't already know this but in episode 2-22 'Be Careful What You Witch For' Piper says, "You have been watching me my entire life". (00:04:45)
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.
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)
The Day The Magic Died - S5-E15
Plot hole: In the episode "The Day Magic Died," Phoebe and Paige first find out that magic is down when Paige tries to orb the unicorn. But, when she tries to orb it, she makes a scrunched up face that would suggest that she knew magic was out and she hoped that she could orb.
Plot hole: The demon is killed when Leo proposes, hence before the wedding. So how is he able to break the cake topper?