The DNS server at 80.241.218.68 that we requested to resolve flurry.com should have blocked resolution, as that is a filtering DNS resolver known to be blocking that domain.
Your answer suggests that the DNS request never made it to the public DNS server at 80.241.218.68, and thus implies that either your router or your ISP redirect your network's DNS traffic to a server of their choice (e.g. Netgear's C7800 has been reported exhibiting that kind of misbehaviour before).