A quick search suggests that only 20% of programmers in general are female, but 30% of Google programmers are female. I'm not certain these numbers are accurate, but if they are, female programmers are over represented at Google.
That would mean Google hired a greater percentage of female programmers than male programmers. That is, if Google hired the top 0.1% of male programmers, they hired the top 0.15% of female programmers.
If we assume two groups have identical distribution of qualifications, the female programmers hired would have lower qualifications, as an obvious consequence of a hiring policy that favors women. That's not saying women are less qualified, it's saying that Google hires women who are less qualified because they want to hire more women than the 20% that sex-blind hiring would result in.
