But not mentioning the actor is what irked the commenters above me. The construction, on the other hand, doesn't matter. It can be done just as easily in an SVO sentence with a "real" agent: "Commenters raised concerns about ...". There, no information about the actor at all.
But people like to add some technical detail to their argument, such as stating that the sentence is written in the passive voice, as if that proves their point. Strunk and White (and the countless people that mindlessly copied them) have made the passive voice the perfect candidate for this, to the point where it becomes an accusation, and any accusation of hiding agency is simply called "passive voice."
But the analysis that the actor is missing is also shallow. In scientific communication, the actor often doesn't matter. It's the why, the how, the what a paper need to answer, not the who. The authors take responsibility for the (unconfirmed) fault. In that sense, there's little to critique about the passage, whereas the commenter makes it sound like a cover-up. If (s)he wants to know whose concerns they were, just say so, and state the reason, but don't hide it behind a (wrong) technicality. That just makes it look like the pot calling the kettle black.