Welcome to the world of journalism. If you want something stated with absolute certainty when the facts don't support that maybe you want to read propaganda.
Well, certainty isn't available whatever the facts! So it's not relevant here.
There's no contradiction between fallibilism and asserting that some scientific explanation is true. This study doesn't assert anything apart from an 'association'. Yet progress is made by addressing theoretical problems, not by looking for assocations, which are everywhere.
As for 'propaganda' I think you've got it the wrong way around. It's the people who applaud this kind of non-result who are seeking a kind of uncritical 'Yay Science' experience.
Those people are called the "lay public" and they're capable of believing that caffeine is both good for preventing heart disease and a major cause of heart disease at the same time.
