[RegulatorCountry]

"And your unknown unknowns."

Those are the ones that'll really getcha.

[sarasmom]

Now calm down!

"Known" is obviously very different from:
"all available and proven evidence points to"
"all available evidence points to"
"available evidence suggest"
"available indications are"
"indications suggest"

So a fed saying something is "known" is either because "it" is either an inescapable fact or utter fiction.