To be clear, there's no definitive evidence either way. Reasonable people can differ in which version they find more plausible. But I think the extent to which a lot of people tell it as certainly being a suicide (and certainly being due to anger over his unjust conviction, he could've committed suicide for unrelated reasons!) is distorting the issue.
But that being said, the coroner’s inquest at the time ruled it a suicide. So we can speculate that they got it wrong, and we can suggest that today we may or may not come to a different conclusion, e.g. “Death by Misadventure”.
But until someone gets that ruling overturned, it seems to me that the appropriate way to describe his death in a journalistic context is to either say nothing (Died in 1954), go along with the official verdict (Committed suicide in 1954), or mention the official verdict and that there are some dissenting views (Died in 1954 by what was ruled a suicide at the time, however some historians now question the finding.)
I feel it’s inappropriate to say “poisoned,” while saying nothing about the ruling at the time, which has not yet been conclusively overturned.
I find the arguments against suicide reasonable, but it’s not like anyone has a conclusive bit of hard evidence that it wasn’t suicide. So it seem to me that if the manner of his death is to be mentioned, the official verdict should be mentioned.
At the time suicide in England was a crime and coroners needed to prove that the deceased i) did something to end their life and ii) had the intention of ending their life, and they needed to prove that to the criminal standard, ie "beyond all reasonable doubt".
Suicide stopped being a crime in England in 1961. http://www.legislation.gov.uk/ukpga/Eliz2/9-10/60
The burden of proof changed from "beyond all reasonable doubt" to "balance of probabilities" after the Maughan cases in 2018/2019.
Maughan case appeal: https://www.bailii.org/ew/cases/EWHC/Admin/2018/1955.html
Maughan case next appeal: https://www.bailii.org/ew/cases/EWCA/Civ/2019/809.html
It would be easier, not harder, for a coroner today to come to a conclusion of suicide.
[from the BBC article] >Prof Copeland emphasises, a coroner these days would demand evidence of pre-meditation before announcing a verdict of suicide,
I'm not sure that's true. Evidence of pre-meditation makes a conclusion of suicide easier, but it isn't required.
There are a lot of misconceptions about suicide, especially about how suicidal people behave. These examples from the BBC article are the kinds of things that seem important but which actually aren't:
> In statements to the coroner, friends had attested to his good humour in the days before his death.
> His neighbour described him throwing "such a jolly [tea] party" for her and her son four days before he died.
The paradox of good mood before self-inflicted death has a few possible explanations. Imagine a person in severe emotional distress. They can't see any way out, and they can't see how their future will work. They decide on a plan to end their life. For that person, at that moment, this is a solution to their problems. They now have something to work towards; they now have a way out.
There are people who dispute Prof Copeland's comments. From what I've read of Copeland's comments he doesn't understand suicidality; he got some facts about the case wrong; and he doesn't understand coroners.
I find this response more persuasive: https://www.turingfilm.com/turing-suicide
So I guess when I say that an argument is “reasonable,” what I’m really saying is, “I get where that person is coming from, and I don’t think they’re unhinged for thinking what they think, or for saying what they say.”
But that doesn’t mean I hold the same views. And without checking everything you’re saying, It seems reasonable too.
Lots of people don’t understand suicide, I don’t think we understand much about mood disorders or suicide (and for that matter, not all suicide is related to mood disorders! Lumping the two together reflexively is probably a sign that I don’t understand suicide either.)
Anyhow, this I do believe: If we can speculate that “Today, we would likely come to a determination of X instead of Y given the evidence,” we can also speculate that today, we’d have much, much better evidence.
And even better, if Alan Turing did commit suicide, and if he was motivated by his persecution, well then, today he would not have been persecuted to begin with. And if he had some mood issues for other reasons, well, while our society is still deeply flawed in this area, it’s still much, much better than it was in the 1950s.
Regardless of what actually happened, the larger story of our social progress around homosexuality and inclusion of atypical people——whether socially or neurologically atypical—- is the thing that matters, and his life’s story forms a part of that progress no matter what exactly happened to end it.