Something Wicca This Way Comes - S1-E1
Continuity mistake: At the beginning of the episode they show Piper running up the stairs to her house in the rain. The umbrella she has is black, with a colored ring around the edge. When she enters the house the whole umbrella has changed to colors surrounding the whole umbrella now. (00:02:35)
Something Wicca This Way Comes - S1-E1
Continuity mistake: In the scene when Piper and Jeremy are in the taxi, Piper gives him a fortune cookie. You can see her closing the box. In the next shot of Jeremy, you can see the box is still open. (00:31:15)
Something Wicca This Way Comes - S1-E1
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)
Something Wicca This Way Comes - S1-E1
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.
Something Wicca This Way Comes - S1-E1
Continuity mistake: When Piper and Jeremy are in the elevator, he pulls a knife on her she freezes him. When the camera shows him from her p.o.v he has this really "snarling" looking face with his mouth open. But when the camera changes the shot from looking at them from outside the elevator, his face is completely different and his mouth is almost closed.
Answer: That was a mistake in the series.
Also, the episode is called 'Babies First Demon' and this alone tells us that it's Wyatt's first time in the field (so to speak) and as the sisters say, they've done a good job of clearing up their own magical messes so far. Nobody really knows how advanced Wyatt's powers are, or will become. That's why the cleaners appear, to nip things in the bud. The Cleaners didn't want to chance that the sisters could clean Wyatt's magic up, just incase they couldn't. Therefore intervening themselves, just in case.