Continuity mistake: After Phoebe jump kicks a warlock and falls to the ground, there is a blonde woman standing next to them. In the next shot of the warlock, when Piper blows him up, the woman is gone. But all of the mortals had been frozen, so she couldn't have moved. (00:37:40)
Continuity mistake: If Leo can't hear the girls call him when HE is underground, he shouldn't be able to hear the girl's call him when THEY are underground and he doesn't know they are at P3 until a few minutes later.
Continuity mistake: Near the end of the episode, in the scene at P3, Phoebe launched a jump kick at a warlock after Paige has been knocked down by a small energy ball. Everybody else in the club was frozen by Piper, but when Phoebe lands she jostles a blonde extra who moves from her pose.
Other mistake: The one demon that knew about the 40s party was vanquished, and he went straight from spying on Paige and Phoebe at P3 to "glamouring" into Leo at the Manor. He had no way of telling Devlin about the 40s party, and yet it was still full of demons waiting to kill the Charmed Ones, with Devlin "glamoured" into Melody as a trap. And Devlin didn't even have that power - the demon that was vanquished did.
Continuity mistake: When Devlin uses the Ring of Inspiration on his subordinate, his hand changes orientation from vertical to horizontal. (00:10:35)
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.