In my experience at other companies recruiters and pretty much no one else has any idea that someone has been blacklisted, until you do all of your interviews and tell HR to hire that person and that's when they tell you the person is on some kind of shit list and we can't hire them. That was an awkward conversation with someone who was basically told we'll be making an offer soon.
What? Hiring is a contract between employer (company entity) and employee. No individual "you" can hire anybody except through the company's official process. If HR says "no we won't extend an offer," a lowly HM extending an offer would be clear-cut fraud.
