Rachel Must Be Dumb as a Post!
She cheats, she lies, she says that she loves him! And now due to her personality deficiencies, her partner compromises their boss and Rachel is saved again!
And Janet compromises her own integrity by continuing her adulterous affair while covering for Rachel's indiscretions. DS Andy is no better.
Rachel is looking so hard for love that she can't see the forest through the proverbial trees. And like a lot of self loathing women, she seeks out men who treat her like dirt AND she keeps going for it.