Visible crew/equipment: While Phoebe begins her "fifteen minutes of channel surfing" she has the burning premonition and cries out, then in the next shot as Prue and Piper rush in, we can see the reflection of the boom mic/pole in the wall mirror. (00:02:10)
Visible crew/equipment: Just after Piper freezes the security guard after she and Prue enter the prison, they are walking along a corridor and the shadow of a boom mic can be seen in the top left quadrant of the screen.
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.