Timing is impeccable: Trump is about to sell a bunch of F-35's to Poland, so let's hit them with a "cluster of damning reports" to sour the deal.
If you read the actual article, you'll see that most problems are either fixed already or aren't as severe the headline would make you believe. But nobody really reads the articles.
In your scenario, who is behind the "cluster of damning reports"? Liberals? Poland? Russia? China? Defense contractor competitors? I agree with the second part of your comment.
Could be anyone. Could even be several parties simultaneously feeding information to the media. The only unlikely party is the competitors, since it's not in their interest (in this case) to shit on Lockheed.
If you read the actual article, you'll see that most problems are either fixed already or aren't as severe the headline would make you believe. But nobody really reads the articles.