Yeah but why do you even engage that question? Synsensa is like: "Here, let me quickly build a hill." and then you're like: "Damn. I want to die on that!" It's not important whether we have a proven case of a false allegation that has brought down a person or not, what's important is that the system that is being used allows for that to happen. Unproven allegations are believed, and come with consequences.
But anyway, if we really, really want to climb that hill, then German Weatherman Jörg Kachelmann is the obvious example here. That's long before metoo of course, but it's basically the same thing. He was accused of rape, immediately removed from his job and called a rapist in the headlines of a number of news outlets. Court found him innocent - not due to a lack of evidence, it was shown that the claims his accuser made, can not have been true, and not in minor details, but the broad story she came up with. He tried to get his position back, but was denied by the tv station because the tv station assumed that it would have negative consequences for them. He was proven innocent, and still had to live with the consequences.