Did you read my response to gergles? No, you'll never get a perfectly unbiased process. But having to justify your opinions with written data forces you to delve a little deeper than you otherwise would, and expose facts that might qualify or disqualify a candidate, not just impressions. It's still wrong, but it's less wrong.
Culture fit is one of the dimensions that candidates are evaluated on. But again, feedback needs to have supporting data. If you didn't like a candidate, you have to say "Didn't have a firm handshake" vs. "Appeared combative and arrogant when faced with a problem he couldn't solve; said 'Google's interview process is a bunch of technical trivia bullshit' before stomping out of the room", so that the hiring committee can judge whether this is just a nit specific to the interviewer or an actual problem that will impact the candidate's prospective teammates.
The reason why new hires don't know their teams is because of Google's corporate secrecy policies: most of the time, the projects they're working on haven't launched, and therefore can't be talked about outside the company. Even then, there are exceptions. When I was hired, I was told which department I'd be working in before I signed my offer letter, who my manager and his manager were, and was given the option of working elsewhere in the company if I really disliked that. My teammate actually negotiated the specific project he'd be working on, and they created the project for him. You need to have negotiating leverage to do this, though: they not only have to want you enough for you to get hired, they have to want you more than the vast majority of other hires, enough that they're willing to bend the rules a bit.
The recruiting/interview process at Google has a lot of problems, but I don't think that either the interviewer/HC split or the whole-company teams-later approach are part of them. Both of these were created to solve specific problems that have crept into the hiring practices of other big companies, and by and large, do a better job at it than the alternatives.
What about the bias that comes from having worked with someone for a few years, and knowing without any doubt that they are awesomely gifted, loyal to a fault, and willing to dive into the breach for the common cause? You cannot figure that out with a sterile interviewing process.
A company does not have to guard against 'bias' other than racial, religious and that sort of thing. 'Bias' towards (or against) people you know is called knowledge.
Culture fit is one of the dimensions that candidates are evaluated on. But again, feedback needs to have supporting data. If you didn't like a candidate, you have to say "Didn't have a firm handshake" vs. "Appeared combative and arrogant when faced with a problem he couldn't solve; said 'Google's interview process is a bunch of technical trivia bullshit' before stomping out of the room", so that the hiring committee can judge whether this is just a nit specific to the interviewer or an actual problem that will impact the candidate's prospective teammates.
The reason why new hires don't know their teams is because of Google's corporate secrecy policies: most of the time, the projects they're working on haven't launched, and therefore can't be talked about outside the company. Even then, there are exceptions. When I was hired, I was told which department I'd be working in before I signed my offer letter, who my manager and his manager were, and was given the option of working elsewhere in the company if I really disliked that. My teammate actually negotiated the specific project he'd be working on, and they created the project for him. You need to have negotiating leverage to do this, though: they not only have to want you enough for you to get hired, they have to want you more than the vast majority of other hires, enough that they're willing to bend the rules a bit.
The recruiting/interview process at Google has a lot of problems, but I don't think that either the interviewer/HC split or the whole-company teams-later approach are part of them. Both of these were created to solve specific problems that have crept into the hiring practices of other big companies, and by and large, do a better job at it than the alternatives.