Hey, author of the blog post here.

I was one of the human book-keepers for this benchmark (the preparer; my co-founder verified the VAT submission once ready), and given that at the time of doing this I knew I was eventually going to use this data for evaluating the models, I was super careful. So I guess this is a "good book-keeper". In the previous company our book-keepers made lots of mistakes; some serious enough that we had to restate our company's accounts.