I would politely suggest that those who question the quality of the work and what the excel error meant for that particular paper and the whole body of work take a listen to this econtalk segment.
Justin Wolfers: "At the end of the day, the folks from U. Mass. Amherst want to claim that they found terrible errors and that Reinhart and Rogoff's negative correlation between public debt and growth is wrong. That's another mis-statement. That even once you accept all of the corrections and amendments of the Amherst folks, it's still the case that countries during periods of high debt tend to be growing slower than during periods of low public debt."
Yes, but what they don't discuss is where the threshold and what the quantitative implications of applying a study like this to national policy is.
R&R still hold out that the threshold is 90%, and that I think is indefensible. Even worse is the idea national policy should be made on this basis of empirical work like this that cannot support conclusions of causality.
The article that you referenced contains this statement:
"Equally, it’s time to abandon the more specific claim that there is a threshold of 90 percent of GDP beyond which the negative effects of public debt on economic growth become particularly evident. This was always a stretch, and is now quite clearly inconsistent with the balance of the evidence. Unfortunately, it’s the sort of sound bite that the media and our politicians find irresistible."
The fact that R&R continue to defend this makes their position untenable.