You’re More Likely to Be Hired If You’re Referred by Someone White

>One startling finding in the report was that the hiring agents who were deemed most anti-black (according to bias testing) rewarded black referrals more than the nonbiased white employers

I don't have access to the study - is there any explanation of how they concluded if one was bias or not? Seems like this is a fundamental component of the study and yet their own results seem to contradict its outcome.