It seems like you are implying that because they might be obfuscating a hypothetical "source" that the findings are invalidated. What would you have the author do, instead?
Without that, they're really just uncritically repeating the story of one biased and routinely corrupt party. Which mirrors the rest of the article, as it seems to be a hit piece setting up a pretext for going after these Really Bad Foreign People. Ostensibly with the goal of further empowering the agencies and broken legal regime that is responsible for the fentanyl crisis in the first place.