Thanks for the precision regarding the hash. Regarding the error, they are logged when a verify_block/transaction returns False, just to be a bit more explicit

Thanks for the precision regarding the hash. Regarding the error, they are logged when a verify_block/transaction returns False, just to be a bit more explicit about what failed. In a real implementation, I guess you would throw exceptions instead (or use some Result pattern), but I tried and it cluttered the code quite a bit, so I went back to logging.