While I admittedly bought into it, the depiction of this whole scandal has gotten a little out of hand when it comes to the motives of the authors involved. The excel error excluded data on an alphabetical basis, and the authors have given their rationale for the two other blunders which are definitely up for debate but still legitimate.
The specific edition of the journal this was published in was particularly less scientific than most other editions in that it didn't require explicit sharing of data (which was still mostly available via R&R's website) and no refereeing or preliminary review. Yet, here we are now, so it might as well have been. To assert that this specific episode shows some bankruptcy of rationality in the field seems a stretch. The legitimate complaints about lack of uniformity and politicization of the field are much broader and less sinister than this specific instance. More than even the other social sciences, this field has the most explicit public policy implications and such problems should be expected.
On the issue of causality, this post
makes a compelling case, perhaps a great starting point, that the causality is reverse, that is that low growth leads to high public debt levels.
Still though I think this may be over-generalizing, and this should be dealt on a case-by-case basis. I believe Europe's situation is a prime example of how certain structures of public debt, particularly when you don't control your own currency, can cause recessions. And still people like Krugman have pointed out that important points of R&R's data set like Italy and Japan clearly suffered their debt malaise as a result of external problems.
The author's attack on the fiscal multiplier seems incomplete. I agree with him and others he's quoted as far as he goes. The common understanding of it generalizes far too much, isn't comparable across countries, time periods, etc. as it is essentially a ROI which can be contrasted to something I guess you could call the private multiplier (perhaps comparable to what he calls the "marxist multiplier"). He even leans towards the intuitive conclusion that the fiscal multiplier is larger during times of recession. Yet the tone that I got was that somehow this is all irrelevant, and in an ironic twist that I think Marx himself, trapped in his Hegelian moment, was victim to is the assumption of the Classical school that public spending itself is irrelevant. Perhaps you could justify this.