OpenDNS worked the way it was supposed to. It wasn't the right DNS solution for this situation.
I also don't think OpenDNS is a tool of censorship, as it is so easily circumvented. I hope my children learn how to circumvent tools of censorship and this can be their first practice... Until then it reduces the risk of accidentally going to phishing websites.
I'm only pointing out that in this spesific case it had nothing to do with the robustness of the application.
More specifically: A better application might have warned you about the failing part so that you won't have to go looking for it. Fixing the problem would still include either replacing OpenDNS or working around it.
However robust an application is it can't handle being fed html ads instead if application spesific json.
When you are finished rethinking this you can go on to think a second time about censoring your wifes Internet access. Do onto others etc....