The experts did NOT state it as fact. Pretty much ever. They couched it in terms as best they knew. If you want to argue that people consuming that and spreading that info put it in bad terms, you can, but I think that's a poor argument in general.

I disagree that people were spreading it in bad terms, if by that you mean the general public. Just look at what the officials actually said. Here’s March 2020:

> “You can increase your risk of getting it by wearing a mask if you are not a health care provider,” Surgeon General Jerome Adams said.

England’s chief medical officer, same month:

> Prof Whitty said: “In terms of wearing a mask, our advice is clear: that wearing a mask if you don’t have an infection reduces the risk almost not at all. So we do not advise that.”

Dr Fauci:

> “Right now, in the United States, people should not be walking around with masks,” said Dr. Anthony Fauci, an immunologist and a public face of the White House Coronavirus Task Force, on CBS’ “60 Minutes” earlier this month. He, like the others, suggested that masks could put users at risk by causing them to touch their face more often.

The WHO advised against it (to your point they did couch their language so much that it wasn’t even clear what they were really advising [1]).

And these are just the ones I could find quickly right now. From memory, the message was even stronger than this and even proliferated in this very forum. There was a time when you kind of had to duck and speak quietly if you wanted to bring up the idea that maybe this anti-mask thing wasn’t settled fact.

1: https://blogs.bmj.com/bmj/2020/03/11/whos-confusing-guidance...