It just sounds complicated for the sake of being complicated. I can't see how being impartial is really helpful here - surely they want people to form relationships and figure out whether someone can actually work on a specific project or problem?
Impartiality is very important when hiring skilled workers. If your hiring process is not impartial, then it's introducing undesirable bias into the hiring decision.
The classic example is sexism in orchestras. Orchestra interviews used to consist of the candidate sitting on a stage and performing their piece for a panel of judges. The gender ratio of performers was terribly skewed, even worse than the software development field is today. Orchestra managers excused this by saying that women were simply not as good -- after all, the judges scores don't lie!
But a funny thing happens if you put the performers behind a screen. Suddenly, all the factors of their gender and race and grooming go away, and new performers start being a lot more diverse. There actually was a bias, a serious one, and it caused orchestras to lose who knows how many excellent candidates.
The current state of the art for programming interviews at big companies is to have the candidate solve actual programming problems, including whiteboard coding. It's not practical to put the candidate behind a screen or modulate their voice, so splitting up the tasks of "interview candidate" and "review interview feedback" is the best that Google has figured out.
You must realize that your orchestra example doesn't apply here. What they did is clean-cut and simple removal of the gender bias. Provable.
Compare this with what google is doing. It would be the equivalent of having orchestra candidates write an "original" tune on paper in 20 minutes and then talk about select topics in music theory and then submit that to a figure skating judge panel.
It's also worth pointing out that Google wants to hire people that will last for more than one project. It's great if you're hired for a specific project, but what about when that project's done?
Since it's data driven, your opinions are nice but apparently not correct; that is, apparently, people are more successful in the company when they are hired by impartial interviewers than by biased ones... The End.
