https://code.google.com/p/google-security-research/issues/de...
> Microsoft confirmed that they are on target to provide fixes for these issues
in February 2015. They asked if this would cause a problem with the 90 day
deadline.
< Microsoft were informed that the 90 day deadline is fixed for all vendors and
bug classes and so cannot be extended. Further they were informed that the 90 day
deadline for this issue expires on the 11th Jan 2015.
> Microsoft confirmed that they anticipate to provide fixes for these issues in
January 2015.
So basically Microsoft asked for an extra month, and they said no, which forced them to move quicker, and fix it a month earlier. Without picking any side of the debate, you can still see what effect the non-negotiation of timeline has on getting patches out as soon as possible.