Continuity mistake: In 3-5 Sight Unseen, we can clearly see Cole turn the air conditioning very cold and open all the windows so that the Prue, Piper and Phoebe can see the invisible demon, and in season 2 when Prue is turned into a man Phoebe asks "did you fix the air conditioning?" But in this episode Phoebe asks Piper why they have never invested in air conditioning.
Continuity mistake: When Paige follows Phoebe into the kitchen and is trying to convince her that she is telling the truth, Phoebe's right earring is missing in the shots showing both women, but it is there when the shot changes to close ups of Phoebe. It is an awfully large earring to be hidden by her hair in the two-shot.
Continuity mistake: In the episode "A Witch in Time," when Phoebe and Piper are going to Miles' work to get him for the first time, Phoebe runs up the steps to his work and she is wearing leather boots with a skinny heel. Then, when she and Piper are running to where the police shoot-out is, Phoebe is wearing tan Ugs. Then, when they get there and Piper freezes the scene and Phoebe is getting the bullets out of the air, she is wearing the leather boots again.
Continuity mistake: When Paige is telling the others she thinks Lydia is the one Cree was after, she says 'I think Lydia was the one who summoned that dust storm', but none of the sisters were present when the dust storm was summoned. They only arrived afterwards.
Continuity mistake: In the scene where Phoebe dangles the slumlord from the roof, the TransAmerica Pyramid can be seen behind Phoebe and Cole. A subsequent shot, after Phoebe tosses the slumlord back onto the roof, is take from the opposite side, but the TransAmerica Pyramid is still behind them, and is much closer.
Continuity mistake: When the Charmed Ones decide to try to vanquish Cole, Paige says that the newest potions they mixed should work, since they're "at least as strong as the ones [they] used on the Source." But they never used any potions that had an effect on the Source.
Continuity mistake: Paige's headstone reports her year of birth as 1975. But in episode 4-2: "Charmed Again, Part Two," Paige spoke with the nun to whom she was given as an infant on August 2, 1977, and Paige is always described as having been "given up at birth" by Patty and Sam.