The Last Temptation of Christy - S8-E15
Visible crew/equipment: At the start, Piper tells Billie she needs to be patient with Christie, and when Piper adds that if Billie needs anything they are just a call or an orb away, the pink tape mark is visible on the floor at Billie's feet. (00:01:10)
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.