The KGB used to specialize in murder techniques that looked, to all but the most careful examiner, like a massive heart attack. Just sayin' ...
Oh, I think the autopsy should be monitored MOST carefully - I’m just saying RIGHT NOW there is no EVIDENCE that it was anything but natural. But there are certainly a good number of people who had means, motive and opportunity. It should be examined very closely ... but there is no evidence, so far, to reasonably lead one to believe it was a hit, so we shouldn’t assume it was. But if it was a heart attack not induced by an outside stimulus, there should be some physical evidence (artery congestion, previously dead muscle, valve irregularities, etc) to show the cause. I hope an independent forensics expert takes a close look at all the results.