Continuity mistake: After the "dirtbag" is brought back to the manor and Piper is ragging on him, Piper gets very angry and decides to blow her husband up. Less than a minute later, Cole says "Back away slowly, Leo." Leo says "What?" and Cole says "She's becoming a fury." Then it shows Pipers hands, which now have long black fingernails, but they just suddenly show themselves right when Cole decides to show up and say she's becoming a Fury. When she blew Leo into orbs there were no long black nails. (00:25:35)
Continuity mistake: During the opening, Piper, Phoebe and Cole are in an SUV and going to find a demon. A shot from in front shows that there is no rearview mirror in the SUV, just a white mark on the windshield. When they turn into the parking lot however, the rearview mirror has returned.
Revealing mistake: When Phoebe and Paige use Cole as bait to lure Piper to the manor, Phoebe levitates and kicks two furies at once. When they show the front shot of her kicking these two furies, we can see Alyssa Milano's stunt double. (00:34:25)
Continuity mistake: When Piper is grieving Prue's death in the mausoleum, Leo's hand moves from cupping her face to resting on her shoulder blade between shots. (00:37:15)
Other mistake: When Piper and Paige are talking at the Social Services building, Paige talks about one of her coworkers, but in the closed captions, the speaker is mislabled "Piper." (00:41:30)
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.