I believe in the odds. And the odds are that any technology that has a high potential to significantly add to surveillance capabilities has been exploited for that purpose either by hacking it or convincing (strong-arming if needed) the technology provider to cooperate.
I don't deny that Google does a lot of great things in general, and in security research specifically. That would be denying the plain facts. But I also do not think that has any impact at all on the relationships the government builds with (or forces upon) large corporations regarding national security.
When the chips are down, the NSA and other TLAs are going to get what they want. Now that tptacek is part of a larger transnational security company, he may find that out firsthand.