True the PNC left Guyana buried under an insurmountable amount of debt. The HIPC program was initiated by the international lending institutions for the most indebted and impoverished nations. The lending institutions, WB, IDB, IMF etc had staff to pull together and help the applicant nations make their case. BJ happened to be the Finance Minister for the first part of the process. The final 2003 application was done by then FM Sasenaraine Kowlessar.
So to say BJ dug Guyana out of a debt hole (which there was) is a bit of a stretch given the fact that it was a global initiative covering many nations and the staff assigned within the institutions to assist the nations to make their case.
Guyana's Debt Service was 96%, as such, was clearly a candidate. But I give credit to B. Jagdeo and S. Kowlessar for supporting the process.
BJ was FM and ended up President, Sasenaraine Kowlessar was FM and, I believe, ended up trouble with the law. Hop these links work!
https://www.imf.org/external/n.../2000/guy/guyana.pdf