Well, I have never shared this before, but...
I have once tasted pork and bacon which had a distinct - and not pleasant - 'edge' to it. Had the animal in question (an older animal, a few years old, and which I knew) been a boar, I would have unhesitatingly said that it was boar taint. But it was a maiden sow.
It was slaughtered on farm by a registered (and very kind and very capable, I knew him professionally) slaughterman, and butchered and cured in a registered facility by qualified butchers. But I have always supposed that the taint (which clearly not everyone tasted, as several people raved about the bacon and pork) was stress, and that the slaughter of this quite large animal had not been as swift and painless as one would have hoped. It's one of the reasons that I personally prefer to find an abattoir where I know they treat the animals well than to have an on-farm slaughter, even though another on-farm slaughter, some years earlier, of a similarly-sized pig, (which I witnessed in fact, having asked to do so) was as peaceful and gentle as anyone could have wished. (And no, no taint.)