I'd like to see your data supporting the assertion that qualified diverse candidates are rejected at greater rates. The thing is he wouldn't of been fired for arguing the opposite claim, this is clearly discrimination.
This has been shown across society, including applications for housing, police stops, punishments in school, etc. I don't know why employment would be the one exception.
https://pmc.gov.au/sites/default/files/publications/beta-goi...
We found that the public servants engaged in positive (not negative) discrimination towards female and minority candidates
...
Overall, the results indicate the need for caution when moving towards ’blind’ recruitment processes in the Australian Public Service, as de-identification may frustrate efforts aimed at promoting diversity.