IMO CD was setting up TD's death by suggesting she was depressed. Maybe he originally framed it to look like suicide? And then the emphasizes "dying so peacefully in her sleep, I didn't even notice she was dead." A blessed suicide would fit with that statement. I guess the coroner, whatever her lack of credentials, unexpectedly didn't jump to the suicide conclusion. This must really have caused consternation in the Chadbo camp: their effort to "control the narrative" didn't work.
I guess, all in all, this family cluster has always thought (still do) they can "control the narrative," and that's what makes them so dangerous. They think they can get away with their story. But now they have millions of sleuthers digging around and calling out their lies; it must be quite the challenge to their worldview.