One other thing about CW blaming his murders on SW that I can't get out of my head - strangling multiple people does not seem to be a crime of "rage." That would seem to take too much grim, steely determination to carry out.
Not that I believe anything he says at all, but the idea that SW came home so late from a long travel night, slept two hours, had an "emotional conversation" with him at 4am-ish, flew off the handle and reacted by running into her sleeping daughter's bedroom to strangle her. Which would have taken several minutes....and then instead of breaking down, realizing she had just killed her resisting, fighting beloved daughter, and breaking down in a heap of a state of grief and distress and horror at what she had done....she still has enough rage and energy in her to leave the daughter she just killed sprawled out on the bed, run into another bedroom, and start killing and overpowering another resisting daughter. And could carry out that level of rage for that many more minutes. And only stopped when CW came in and instead of stopping her, his reaction to her is "rage" - not fear, horror, distress at the state of his daughter - but his reaction is to strangle his wife instead.
These weren't quick deaths and to do consecutively would seem to require more focus and methodical, emotionless carrying out a grim plan than spontaneous crimes of passion and rage - too much sustained effort for too much time.
I would honestly believe high altitude sickness or twinkies made him do it over his version of events.