I too was surprised when AC's autopsy results were finally released and indicated that he died of natural causes. Seems there shouldn't even be such a thing as a "natural" cause that would take someone's life at age 51. That's not natural.
But if AC's death WASN'T due to natural causes, I would've guessed suicide way before I guessed murder. Other than ZP (or JM?) there just weren't any other murderous "conspirator types" around in the week leading up to his death. Yeah, I suppose you could try to trick him with some supplement pills or "new" meds that you'd slipped him earlier, but that'd be a tough switch and sell. And I think it's much harder these days to mix up a drink containing antifreeze and have it not taste like, well, antifreeze. And coroners, I think, are catching on to that one.
No, my guess is that AC was enormously stressed. Stressed to the bone. Not a happy camper. No longer a clown. Feeling nothing but extreme guilt, shame, and fear - and beginning to think he just might wind up spending the rest of his life in his own private Idaho cell. I think there may also have been some deep seated self-hatred pathology stuff going on as well, but that's jmo.
Alex had just committed several unconscionable and heinous crimes. He might've convinved everyone in the cult that he was on board and faithful with all that LV, CD, MB, MG, ZP, and others were spewing about mortal probations, the 144k, zombies and stuff, but I don't think he really really believed. He just wanted Lori's approval. He just wanted attention. He was lost and just wanted love - and as a kind of sociopath (IMO) he'd do anything to get it.
So the crimes had to be weighing on his concience. He'd just gotten married to a woman he didn't love (and who certainly didn't love him). His sister appeared to be gone from his life (again) forever (and forever again?). The cops were surely closing in. And Alex Cox didn't even want to be Alex Cox anymore: he changed his last name to Pastenes. What a mess he had made of things.
And based on MB's reports of their last phone conversation, I strongly suspect that AC either knew he was dying, or knew he about to die, when the two of them were speaking on the phone. I think at that moment he was either already in the process of killing himself, or was just about to begin the process of killing himself, and MB could sense it.
The autopsy report has definitely been frustrating to a lot of us. I have almost felt that this particular autopsy report should have been beyond reproach or question, because if there was ANY death in this whole bizarre case that authorities (and a respective coroner) would've and should've KNOWN to look especially hard for any hard-to-find, difficult-to-detect, kryptonite, periodic-table-type poisons, THIS WAS IT! They couldn't have missed it! Could they?
Immediately after the (disappointing) results were posted, I suggested that Alex's PE could possibly have been caused by injecting air into a vein (an air embolism). Air injections/embolisms have been used in many suicides and murders in the past, but it's not the easiest method, mainly because it apparently takes a good bit of air. That aspect of it might complicate things in a murder, but it probably wouldn't deter someone attempting suicide.
And a suicide-by-air-injection-resulting-in-PE definitely doesn't fit into a nice package crime involving poor TD (using the same method, only for murder). You would have had to first somehow sedate her, and then inject her with the air. Even if the air embolism PE method couldn't be detected, the sedation drug probably could. But I don't really know what I'm talking about, so I think I'm going to bed.