> organizing the world's information and making accessible
That's a corporate business objective. It doesn't give every Google employee the right to publicly say what they want, when they want, using company systems, and when engaged in their job.
According to the original coverage, his (and other Google employees') opinions on the topic of diversity in hiring was requested. He originally put his response up on a group explicitly created for this discussion.
He never sent it to Google at large - someone else did that in outrage at his opinion. Just as someone else leaked it from being internal to Google to the media.
That's a corporate business objective. It doesn't give every Google employee the right to publicly say what they want, when they want, using company systems, and when engaged in their job.