And just consider how some people might have felt about the immediate Heirs-but-one to the Throne being presented with step-siblings of somewhat dubious alien extraction...

As to an unlikely means; what other could have led so inexorably to that useful inquest verdict to let anyone who might have been involved off the hook?

And I would add, most vehemently, that, believe it or not, in pretty well all cases I loathe, detest & despise conspiracy theories ~~ They did, so, land on the Moon, not in the Nevada Deaert; Myra Hindley did die & was buried, they didn't avoid public protest by letting her out on the quiet and burying an empty coffin...

But I make an exception for Diana's & Marilyn's unbelievably convenient-to-the-powers-that-be deaths, just because they were so incredibly [I choose the word carefully] convenient.