Something Wicca This Way Comes - S1-E1
Visible crew/equipment: When Piper and Phoebe are standing beside the car Piper kisses "Nancy Drew" goodbye, and Phoebe continues to tell her sister, "We're known as the Charmed Ones," then in the next overhead shot the reflection of the boom pole/mic is visible on the car's windshield, just as Piper drives off. (00:20:10)
Something Wicca This Way Comes - S1-E1
Visible crew/equipment: When Jeremy wakes up in the freight elevator he rushes off to find Piper, and when it cuts to Piper and Prue in the living room, the reflection of the boom mic is visible on the glass of the framed photo, behind the couch. (00:36:20)
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.