So no, it wasn't "science", it was deliberately misleading public statements.
"We do not currently recommend face masks in public settings since the scientific evidence around the effectiveness of face masks in combatting the spread of infection is unclear. However, there may be situations where face masks can be useful despite the uncertain state of knowledge about the effects.
Face masks must always be seen as complementary to other recommendations: stay at home when you have symptoms, wash your hands regularly and keep at a distance from others."
- https://www.folkhalsomyndigheten.se/the-public-health-agency...
As a source for this they have this page with 37 different papers/studies: https://www.folkhalsomyndigheten.se/smittskydd-beredskap/utb...
So... the science depend a lot of who you ask and the context of the statement.
People who have admitted publicly to engaging in a misinformation campaign are now considered to be the authorities against which dissenting views will be judged misinformation.
As I was looking at this back in February / March there were plenty of studies dating back years or decades, looking at N95 and surgical masks and their role in preventing the spread of respiratory infections. The WHO and all western countries were claiming contrary to those studies that masks do not work and should not be worn. Then when things got more critical, EU countries did a 180 and started making masks mandatory or recommending them. Finally the WHO commissioned a meta-analysis and lo and behold in June it turned out that masks do work.
The Swedish public health agency's quite lonely in the opinion it holds now. But even so, I don't see why Sweden's or its health agency's opinion should count for anything in all of this. If anything I'd rather listen to what Taiwan, the KCDC or CCDC have to say, since they actually have some results to show besides empty words and opinions.
They will say wherever they have to say to maximize profits and reduce losses
Now the damage is done, and more people distrust Science.
History has shown that blindly following uber global bodies like the WHO can have a massive negative outcomes even with best intentions.
When exactly did following the UN or any other body result in desaster?
https://www.theatlantic.com/health/archive/2020/04/why-world...
UN specifically
Israeli occupation (1948-Now) Kashmir dispute (1948-Now) Cambodia violence (1975-1979) Somali civil war (1991-Now) Rwandan civil war (1994) Srebrenica Massacre (1995) Darfur conflict in Sudan (2003-Now) Iraq invasion (2003-2011) Rohingya Crisis, Myanmar (2017-Now)
There were UN troops in Srebrenica, and their failure is a well covered topic. There are multiple resolutions against Israel, the first from the Suez crisis. Most just get ignored, not the least due to US vetos. The Iraq invasion was a purely US thing that had nothing to do with the UN, some NATO members supported it but not all.
There is a difference between causing disaster, which the UN didn't, and failing to prevent it, which the UN does. Expecting perfect results from one side and no results at all, or close to jone, from the other is just disengnious.
WHO has a global outlook and you have a person story. Those two conflict more often than not. Telling you masks don't work and then telling you they always worked and you must wear one is a big messaging error that has cost many lives. And the reasons behind are political. Trust with me has been broken.
If it's important I'll include a link with detailed context for each and throw in a few more examples for you.
https://www.google.com/amp/s/www.trtworld.com/americas/twelv...
I remember early on debating people whether masks worked and they pointed to the lack of scientific studies.