Microsoft have certainly spread anti-GPL FUD for years, and this would be highly consistent with their previous behavior.
They've also worked at arms-length through astroturf campaigns, lobbying groups, and various companies (the Alexis de Toqueville Institute and Wang v. Netscape come to mind). Multiple times.
And the key personnel at Microsoft then and now remain.
I see it as an institutional disease, and view them with extreme skepticism and prejudice.
Of course, he could just be an attention-whoring, not-too-bright attorney.