Good question -- but I have to say "almost certainly not", for two reasons.

First, I haven't had any email from Microsoft about this -- and for all that Microsoft has a reputation for being bad at security and not supporting open source software, they do take their responsibilities seriously when it comes to inter-vendor coordination.

Second, the details I've seen relating to this suggest that it relates to connection hashing -- which is relatively new, and thus is unlikely to involve code from the BSD stack which Microsoft imported so many years ago.

Actually unlike the previous TCP/IP stack I believe the Vista/Win7/Serv2008 stack is new from the ground-up.

They rewrote it so carefully that they duplicated the same teardrop bug they created back in windows 3.1/95 and didn't fix for half a decade.

Now that is almost mean.

As FreeBSD Security Officer I don't see anything unreasonable about that question -- it's the first thing which occurred to me, too.

But seriously--if this bug was in BSD, wouldn't we know it already?

Not necessarily. Just a few months ago I fixed a serious vulnerability in FreeBSD which had escaped notice for over 13 years.