Revealing mistake: The character Ramus (the elder) changes actor when Leo jumps and orbs to get him away from the attack of the Aggressor. The actor's stand-in is visible instead. (00:18:52)
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. (00:25:25)
Continuity mistake: When Leo and Ramus are talking in front of the bay windows, the door behind Ramus switches from closed in the wide shots to open in the close-ups. (00:31:50 - 00:33:00)
Continuity mistake: Just after 'the Aggressor' tears the picture of the girls, they all change back to their normal clothes, however in one shot, Paige's arm is visible and she is still wearing her costume. (00:34:35)
Continuity mistake: The drawings of the sisters, change from when they were in the book, to when the Aggressor tore the paper. (00:33:55)
Continuity mistake: In the opening scene in the club with the DJ playing, they have an overhead shot of the club. In the lower right hand corner we see Paige and Dave talking with Leo and Piper, but after the scene cuts out Piper is just walking in. This can't be since we already saw them talking.
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.