Oh please, we know exactly what the coroner meant by "of this type". He meant homosexuals. He (and many many other people in the medial and government at the time) thought homosexuality was a mental illness and very unnatural affliction.
The problem as far as the establishment was concerned was that Turing had access to all the nation's secrets and he was inviting anyone home he fancied... That he was gay was just a pretext for what happened next.
Although they were aware of homosexuality, and likely to have practised it, don't pretend they were OK with homosexuality. They viewed it as something that one should grow out of. That there was something unnatural about grown men doing it. That it wasn't possible to have a real same-sex relationship. That it was a unseemly, unnatural thing.
If Turing had been inviting random women to his house he fancied (which would have happened to lots of other men in his position), it would not have been nearly as much of a problem.
Turing didn't turn off his homosexuality and settle down in a nice fake loveless marriage (with a woman) and keep up appearances.
Alan Turing, The Enigma, pages 496 onward, several UK men suddenly removed from secret work in early 50s.
http://www.thedailybeast.com/articles/2012/06/23/alan-turing...
I was previously unaware that this was such a common phenomena.
"It's a mental illness, don't blame the person", is kinder than "They are filthy amoral degenerate", but not as kind as "It's as valid a relationship type as heterosexuality"
Interesting that he cites the half-eaten apple as definitive proof of suicide, when (if the OP is correct) Turing habitually ate half an apple at bedtime, and this one was never tested for cyanide.
Whether or not the ruling class was "used to homosexuals," their attitudes towards them were far from universally accepting or enlightened.
"Of this type" means that he was an out of the box thinker and hard to predict. It in no ways should be understood as you are stating.
I mean, the coroner must at least have known that he had a chemistry lab, working with dangerous chemicals, in the house. That's way more unusual than gaying it up.
Do you think a dead man with breasts would have gone unnoticed by the coroner? Do you think he might have wondered why Turing had breasts?
It's quite reasonable to think that the coroner would have known that he was homosexual, and it is quite reasonable to think that would have been viewed as a flaw, since, you know, the whole state-sanctioned "choice" between prison and chemical castration thing.
That seems quite plausible. The coroner would be aware of his criminal conviction as a matter of course, but might have relatively little information about his profession.