It is obviously true that the applicant pool for tech jobs is dominated by male candidates.

It is less obvious but equally true that women are mistreated in interviews more often then men are. I did not believe this even a little bit up to 2004. I had, after all, hired women; once, I even hired one as my boss. Then I watched a woman go through a series of tech interviews with other people. Oops.

This person has the same broken mental model that I had: "I'm fair to both women and men, and I get very few women applicants, so the problem must be lower in the stack." There clearly are problems lower in the stack, but that's not all that's wrong.