Visible crew/equipment: In the scene where Prue comes home and finds Andy inside the manor. There is a shot where if you look behind Andy's shoulder you can see half of the body of the director in the background in the observatory room sitting in a director's chair. (00:16:00)
Continuity mistake: After the Grimlock kidnaps the child getting the ball, Prue goes after it. But the demon opens a hole in the earth and jumps through it and it closes. Prue then reaches the spot where the Grimlock disappeared and she is surrounded by dead leaves and trees. Then it goes to another shot of Prue turning around. Suddenly the trees and dead leaves are gone and she is standing in an open area with green grass and no trees.
Continuity mistake: In the previous episode, Piper tried out for a job as a chef at a restaurant called "L'Opera Ristorante" and was hired by Chef Moore. Then in this episode, she works at a bar and restaurant called "Quake," but she talks about Chef Moore quitting and leaving her in charge of the establishment, so it's not meant to be a different place.
Continuity mistake: In the teaser, the demon attacks Dr. Mitchell, killing him and also destroying his irises. His eyes turn white, and later dialogue confirms that the irises were gone from his eyes. However, when the Charmed Ones find his corpse, his eyes are open and his irises are visible. (00:01:10)
Continuity mistake: At the end of the episode the newspaper Prue is holding keeps changing from facing the camera to facing her. And as she turns to the house she drops her hand (and the newspaper) to her side but in the next shot she is holding it to her chest again. (00:40:25)
Continuity mistake: When Prue describes the way the warlock Matthew traveled instantaneously, Melinda tells the sisters that it's called blinking, and that Matthew "must have copied it from another witch." But later in the series, every warlock encountered by the Charmed Ones had the ability to blink, and it was considered exclusively a warlock ability, meaning that no witch would have had it. (00:21:30)
Continuity mistake: In this episode, Leo tells Phoebe that white lighters are sent to their charges by "a group of elder white lighters known as the founders." However, by later seasons in the series, the word "founders" was never used. The leaders of the white lighters were simply known as the "elders." (00:14:15)
Continuity mistake: At the beginning of the episode we see a man standing in the rain in front of the sisters house. After he starts walking away, they show a completely bare tree in front of the house. The next morning when Piper is driving away, they show the same tree with leaves and flowers on it. Trees do not grow that fast.
Plot hole: When Prue first releases Matthew, he blinks several times, then blows out the windows and jumps out. Why would he do this and reveal who and what he is when he could have simply blinked? Obviously it was just a way to get the police involved so Andy could be chasing Prue through the episode.
Continuity mistake: In this episode one of the shape shifting demons from across the street attempted to take the book of shadows out of the house. He managed to carry the book to the door, but could not take it past the threshold of the house. But in the later series it is always stated that evil cannot touch the book of shadows.
Continuity mistake: Prue finds Brendan, as a warlock, over the corpse of Father Austin. He runs away and she pursues him. He insists that he "didn't hurt Father Austin. [He] found him like that." Prue counters, "Before or after you turned into a warlock?" His response is, "After. When I saw what [my brothers] did to him, I was crazed. The rage turned me into a warlock." So doesn't that mean that he found Father Austin before he turned into a warlock, not after? (00:17:55)
Plot hole: Throughout the series, it's established that good witches don't freeze. In this episode, however, Little Piper freezes Future Prue and Piper when they come back to the manor to "kidnap" their younger selves. Simply because the Charmed Ones reason that only one "set" of sisters (past/future) could have their powers doesn't mean that Future Prue, Piper and Phoebe aren't good witches. In other time-travel episodes, the sisters remain immune to freezing and are still able to say spells make potions, meaning they are still good witches. For example, in Season 8 "Forever Charmed," Piper and Leo go back to 1975 (the same time-period as this episode) using Coop's ring, trying to find when Phoebe is alive again. However, when a startled Patty tries to freeze them, only Leo freezes. Piper does not, though she likely cannot use her freezing/exploding power in this time.