I dont think that opendns were broke, i think the routing to them was. Opendns played a part in the outage as changing dns allowed me to access sites i couldnt on opendns (some still were down mind)

So maybe the route from opendns to coms via Enta is different to the route taken on say google dns to coms via enta. And it was the routing that was screwed. All guess work mind but changing dns helped for me