Gidgit, it must be a behind the scenes function of C4D. Check out this image, the wires are C4D at Sub-d level 2 the render was set at sub-d level 3, I exported the weighted hypernurbs obj, due to the render setting the resulting model is at sub-d level 3, I opened it in Silo, as you can see no additional edge geometry has been added.
Pretty cool eh.