> If you say wait a second, but one of those is a fact about the world and the other is an insane conspiracy theory, then to them you're now a censor, an opponent of Free Speech.
No, if you remove the video from YouTube on the grounds of "removing false information" you're a censor. This is what has happened to e.g. Alex Jones, Milo, and many others for example.
By all means, leave a comment denouncing their idiocy. Make a response video showing why they're wrong. Whatever. But don't remove the video FFS. It just makes them believe it more.
You said it yourself: "the other is an insane conspiracy theory". That's obvious to you, and its obvious to 99% of people. So why do you feel the need to remove it?