Remember the lab leak conspiracy theory, that got people banned on the spot? Every fact checker would tell you there's no scientific basis for it, every scientist worth of their name is opposing to it and it's a complete fabrication spread around by conspiracy nuts. Except it turned out not only it is not so, but people who said it
knew it wasn't so and were lying because of vested interests, which they failed to disclose and hoped to keep hidden, but "conspiracy nuts" revealed it and the house of cards collapsed. For example:
https://www.politifact.com/li-meng-yan-fact-check/
Note they didn't say with scientific humility "we do not know if that scenario actually happened, more data is needed, it's too early to make the conclusion". They say "it's ridiculous and debunked" and rate it "pants on fire" (i.e. an obvious outrageous lie). They act as if they are the ultimate authority with absolute knowledge of the facts and expertise to make such calls - while they don't have neither the facts nor the expertise. And this happens again and again.