Well well, it turns out that the original OAS report that claimed fraud in vote counting was based on faulty statistical analysis - see
https://www.nytimes.com/2020/06/07/world/americas/bolivia-election-evo-morales.html.
If you dont remember, this was the one that made Morales agree to a new election, and an eventual coup leading to right-wing dictator Anez.
Now the OAS is saying its moot - "Statistics don’t prove or disprove fraud. Hard evidence like falsified statements of polls and hidden I.T. structures do. And that is what we found". And the article says that the OAS consultant who did the work "did not share his methods or data with the authors of [this new study], despite repeated requests".