The psych studies on unconscious racism are kinda scary tbh. There are studies where they send out identical resumes with only changing the name to be a typically white name or black name and the white names get more requests for interviews. There's the old doll study where kids of different races tended to rate white dolls more highly than black dolls (and even the black kids in the study were usually doing this too). Unconscious racism and racial bias are probably definitely things that happen. In the NFL, an equal or less qualified white coach might get the nod over a black coach because he still seems like a better candidate.
I dunno about the Rooney Rule. It's got quotas teams need to meet for minority hires now and meeting quotas comes with all sorts of baggage. Teams are going to hire less qualified people to meet the quotas, and they're also going to hire more qualified people who seemed less qualified because of a racial bias too. If it's more of the former, then you'd want to drop the rule. If it's more of the latter, keep it until you find a better system. The trouble is we have no way of actually knowing what the rule is really achieving.