Continuity mistake: In the episode "A Witch in Time," when Phoebe and Piper are going to Miles' work to get him for the first time, Phoebe runs up the steps to his work and she is wearing leather boots with a skinny heel. Then, when she and Piper are running to where the police shoot-out is, Phoebe is wearing tan Ugs. Then, when they get there and Piper freezes the scene and Phoebe is getting the bullets out of the air, she is wearing the leather boots again. (00:06:45)
Visible crew/equipment: After Bacarra takes the human heart from the witch it cuts to the Halliwell manor, and as the camera pans to the right we can see lighting equipment and the boom mic (with a white striped tip) at the top of the screen, then in a following shot from the same direction the boom mic is visible again. (00:30:55)
Character mistake: When Miles is shot, the cops apparently don't think it's necessary to tend to him to see if he's okay.
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.