The informant is indeed the neighbor, and everyone sees it... except David. He casually enters the compound looking for weapons but fails. And David thinks he can convert him.
We also see the underlying problems with the cult: polygamy (of course) and statutory rape of a 13-year-old. To solve these problems, the young blonde marries Thibodeau.
And at the FBI, we see that snitches to get stiches. So the negotiator will unlikely file a complain because others have dirt on him too.
Final rating: 4.2/5