Be Careful What You Witch For - S2-E22
Continuity mistake: When Phoebe and Piper are leaving to go get Prue, Piper kisses Leo on the cheek and there is a lipstick mark on his cheek. Then the shot goes to Piper then back to Leo, and the mark has gone with no time for him to remove it.
Be Careful What You Witch For - S2-E22
Continuity mistake: At the end of the episode, when Prue shuts the door magically it shows the inside of the house. There should be a doorway parallel to the front door that leads from the foyer into the dining room, but instead there is a wall.
Be Careful What You Witch For - S2-E22
Continuity mistake: When Piper and Leo find the genie at the restaurant, look at the girl in the background, when Piper freezes the time, first she's talking to someone, then she's looking at a menu.
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.