Thank You for Not Morphing - S1-E3
Factual error: At the end of the episode the girls are waiting for Victor. He doesn't show up but sends a package containing a home movie. As they are watching it, they see Christmas when they are little girls. Phoebe can't be more than 4 yrs old, 5 at the most. Since she was born in 1975 that would make the home movie take place in approx 1980, but she gets a Wedding Day Barbie, which didn't come out until 1996.
Factual error: In the opening scene in Salem, Melinda Warren is going to be burned at the stake. But in the real Salem trials, no one was burned; all of the people convicted of witchcraft were hanged.
Factual error: Little Piper (from 1975) has blue eyes. She should have brown eyes, like present day Piper.
Factual error: Melinda Warren says that after Matthew turned her in to the council, she was burned at the stake for being a witch, except witches were not burned at the stake, they were hanged.
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.