Revealing mistake: Throughout the series, Finola Hughes appeared as Patty, the deceased mother of the Charmed Ones. Although Patty died in 1978, she sometimes appeared in flashbacks and time-travel episodes that took place in the mid to late 1970s, and other times she appeared as a ghost. However, over the eight years of the series, Finola Hughes aged noticeably. Patty was born in 1950, so she should always have been either a young woman in her mid 20s, or an unaging ghost having died at 28.
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.
Revealing mistake: When Mark (as a ghost) and Piper leave the hotel after he asks for her and Phoebe's help, he bumps into the handrail as he walks down the steps.
The Truth Is Out There... and It Hurts - S1-E8
Revealing mistake: When Phoebe asks Piper what she thinks of her boss, you can see that Holly's tattoo has been covered up, because that part of her wrist is darker than her skin. (00:17:15)
Suggested correction: Maybe Holly covered it up with makeup because she isn't supposed to have tattoos for her job? A lot of jobs still don't allow piercings and tattoos today but all those years ago it was even harsher.
There are multiple instances of covered tattoos during the early seasons. I noticed it the most on Alyssa's back tattoo.
Which Prue Is It, Anyway? - S1-E16
Revealing mistake: When Pink Prue is stabbed, they show the warlord over her, with the sword supposedly having stabbed her body. It is very obvious that the sword is not actually in her, but about a foot away from her body, closer to the warlord.
Revealing mistake: In the scene where Penny uses her powers at Nicholas and throws him on the dining table, it is clear that the table is a fake one simply made of simple wooden boards.
Revealing mistake: Prue is needed in the storm drain to rescue Piper, who is stuck in a hole bottomed off by a metal circular guard. Prue uses her power to levitate the metal circle to her level. When the camera pans out, the metal rods used to actually levitate the metal circle are visible. (00:36:25)
Love Hurts - S1-E21
Revealing mistake: After Piper saves Leo, they meet with Phoebe and Daisy downstairs near the living room. Before the darklighter appears, smoke from a fog machine can be seen at the left of the shot to magically transition to the computerized effects. (00:33:45)
Revealing mistake: When the sisters are talking in the kitchen about Phoebe crashing Prue's car, whenever Phoebe turns around you can see a distinctly grey patch of skin on her shoulder where one of the actress's tattoos is covered up.
Revealing mistake: When Phoebe opens the cupboard and the human pig falls on top of her, you can see that it's a stunt double in the far shot.
Revealing mistake: When Maggie Murphy climbs onto the ledge of the roof to jump off you can see the surface of the ledge dipping as if it was foam.
Revealing mistake: The sheet-covered body of Charlene that is being moved by the police has obviously got a head, despite the fact that she was meant to have been decapitated.
Revealing mistake: When the pawn shop owner jumps through the glass door, it is painfully obvious that it's a stunt double.
Revealing mistake: When Phoebe punches Dr. Williamson, it's easy to tell that she doesn't really punch him.
Be Careful What You Witch For - S2-E22
Revealing mistake: During the search for the Dragon and teenage Prue, Phoebe's wearing a red top and red jacket, but when Phoebe lands on the ground we can see the bulky beige material of the stunt vest at her back, under the red top and jacket. (00:34:05)
Magic Hour - S3-E2
Revealing mistake: In the attic when the sisters are talking about the "rutabaga," some of the shots of Piper are reversed, her "broken" eyebrow is on the wrong side.
Revealing mistake: When Leo dropped the Grimlock potion, it was obviously fake when it hit the ground.
Revealing mistake: When Prue is practising using her powers while astral projecting, when Phoebe walks away to go see her in the attack you can see the makeup they used in an attempt to hide her tattoo on the right side of her back. It looks as though she's been bruised there. (00:00:43)
Revealing mistake: At the end when Prue is fighting the demon you can tell she is holding on to her safety harness when she is in the air kicking him.
Power Outage - S3-E7
Revealing mistake: When Astral Prue kicks Leo/Balthazar in the face during the training drill near the start of the episode, her foot misses his face yet he still reacts as if hit.
