It appears that it was more than a simple Excel coding mistake.
And it is a bit of a scandal, really.
Here are the authors of that report which was used to make the case for austerity.
Carmen M. Reinhart is the Dennis Weatherstone Senior Fellow at the Peterson Institute for International Economics. She was previously professor of economics at the University of Maryland.
Kenneth S. Rogoff is the Thomas D. Cabot Professor of Public Policy and professor of economics at Harvard University.