From my experience, I agree with this. I interviewed at Google in 2014. I prepared extensively. However, I bombed the interview. The interviewers genuinely wanted to see how I think. I am not brightest guy around and couldn't provide great insights in my solutions. I got same feedback from recruiter.

Just came here to say that from my limited experience, I concur with this comment. Google also has improved their feedback loop after the interview, which I find severely lacking in other companies with similar interviewing styles.