Also, Google does employ a quality team.
Some of these sites might have been given authority and/or rank manually.
Case in point:
I just did a SEO analysis for a swiss site in a competitive environment. The guy consistently ranks 3rd or 4th place with virtually no backlinks or PR.
But he is one of the best known players in that industry in Switzerland. The name is known, the site is quite old and one of the sites to turn to.
but in normal SEO terms, the site should not even rank in the top 30.
::emp::