Seriously what changed that took us from "Person accused of a crime has to overwhelmingly prove they are innocent" to "A person has to prove that they reasonably didn't commit a crime"? What hit those scales so hard?
At least in terms of presumption of innocence as we know it, it was indeed the Inquisition that established this standard. Civil and common law adopted it afterwards, which proceeded to then cover a good chunk of the world during the age of imperialism.
Who is PlumpHelmetPunk?
PHP is one of those fancy fellows who were at one time called Let's Players, and he's great. Also does professional photography, and should do more hitbox streams because I am cold and dead without them. His house burned down some months ago because his neighbors are idiots and set an entire forest on fire. I believe his forum account is A Dwarven Smokeologist, not used very much. Also goes by Amnesiac Jack in some places. Has the voice of a particularly rugged noir detective, but doesn't talk about dames as much.
I think that even if the formal "innocent until proven guilty" thing is recent, the basic idea is old. You need to prove that someone committed a crime, you can't just execute anyone who doesn't have an alibi.
This is only technically true. Many legal systems did have standards beyond mob execution, but for most of history that standard was that you needed a confession. And you were going to get a confession whether the accused was guilty or not, because torture and other such incentives were the game of the day. You might want to check out the stories of Judge Dee, who lived in China at a time where any confession
not obtained through torture was considered suspect, because why would anybody confess their crime otherwise?
It was all very much like the Dominion from Star Trek, where the purpose of trial and judgement was more about the satisfaction of the public mood and the supremacy of the wisdom of the state than restitution to victims or anything about the modern idea of justice. Though one could argue that even trials today are only ultimately about that...