My reading of GP disappointed post was that they were accusing them of the latter; which is, in my opinion, underserved here.
There's a difference, but I don't really see the "world" of difference. They both seem like fundamentally irresponsible journalism. Case (a) should never happen because there's an assumption of due diligence, and case (b) should never happen because there's an assumption of truth-seeking. Not doing due diligence is pretty close to ignoring (or at the very least not caring about) the truth.
In the world we’re living in, with the incentives of modern journalism being what they are (and the state of gaming media industry specifically), I’m willing to cut more slack to people writing about things outside their comfort zone.