Thank You for Not Morphing - S1-E3
Visible crew/equipment: In the scene where Prue comes home and finds Andy inside the manor. There is a shot where if you look behind Andy's shoulder you can see half of the body of the director in the background in the observatory room sitting in a director's chair. (00:16:00)
Visible crew/equipment: When Piper is taken by Wong's men Mark shouts for help, and just as Prue tells Phoebe to call 911 from the car, the blue tape mark is visible on the rug beside the table, where the sisters had been standing before rushing out. (00:36:05)
Visible crew/equipment: When Prue is flicking through TV channels, just as Phoebe walks into the bedroom and stands beside her sister, we can see the movement of the camera operator and camera in the reflection within the standing mirror, near the door. (00:34:05)
Visible crew/equipment: After Piper takes the picture of Tony Wong holding the newspaper, when she and Mark quickly drive off, we can see the actors' large yellow T-mark taped to the ground near Wong and his men. (00:28:35)
Visible crew/equipment: When Aviva tells Phoebe that she wants to go upstairs because she's not feeling well, Aviva walks into the bedroom and just as she grabs her backpack part of the T-mark is visible on the floor where she stands. (00:33:45)
Wicca Envy - S1-E10
Visible crew/equipment: After Jaime tells Prue that she's the hardest working woman he's ever met and believes she's innocent, Prue walks into the office to access Hannah's computer, and just as Prue sits down and moves closer to the desk, the blue T-mark is visible on the floor, under the office chair. (00:24:30)
From Fear to Eternity - S1-E13
Visible crew/equipment: When Andy walks into the manor to speak with Prue, just as she tells him it must be bad news, we see the reflection of the boom mic on the glass door. (00:09:45)
The Wendigo - S1-E12
Visible crew/equipment: When Phoebe joins her sisters in the kitchen before her first day at work, the reflection of the moving boom mic is visible on the glass cabinet, at the top of the screen. (00:10:05)
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)
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)
I've Got You Under My Skin - S1-E2
Visible crew/equipment: When Prue walks into the manor and sees Brittany in the foyer, we can see the boom pole moving at the top of the doorway leading to the dining room. (00:35:20)
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.