Has nothing to do with doctrine. Has to do with a culture of isolation and a mentality of moral superiority that I have personally experienced dozens of times.
Though I don't have firsthand experience w/ the CoC, I know firsthand of other denoms with the same problem. I'm not saying it drove this woman to do what she did, but it probably didn't help their marriage.
You are describing David Koresh like cults, not mainline evangelicals.
Typically people under that sort of control do not act out as she did.
Coupled with the fact that she was embroiled in a Nigerian check-kiting scheme, your little fantasy is more about your prejudices than any facts of this case.
That's not the culture I've found. I wouldn't expect it in general nor look for it. Yes, some people fail and lapse into an unchristian attitude of moral superiority. We can read a concentrated account of people who failed in the book of II Timothy, but that didn't shake the apostle Paul's faith as he stared death in the face.
Moral superiority? What do you mean?
From the husband?