People started figuring out some details about the vulnerability from various public sources (Linux kernel development, previously published security research), and it was getting a lot of media/internet attention.

The Google blog post from yesterday (https://security.googleblog.com/2018/01/todays-cpu-vulnerabi...) says:

> We are posting before an originally coordinated disclosure date of January 9, 2018 because of existing public reports and growing speculation in the press and security research community about the issue, which raises the risk of exploitation.

Given that the CRD/NDA came from Intel and that spectreattack.com is hosted by the University of Graz, I'd assume that that was a one-sided CRD.

See my answer at https://news.ycombinator.com/item?id=16068510 .