I think Russ's point is that the first picture, with the path and the road forking off from one another, looks extremely flat. "overdone HDR" often means popped colors, halos all over the place, and ugly tonemapping. What Russ means, I suspect, is HDR that is taken to the extreme of crushing all the shadows and modeling out of existence.
This is also a way you can use HDR and you can certainly argue that it's "overdoing it". I think there's the potential for a genuinely new aesthetic here, one that uses things which are not shadows to solve the problems that shadow and modeling usually solves for us. I don't think this picture is a good example, though. It just looks crummy and flat. The problems normally solved by shadows and modeling are not solved, nor are they defied, they're simply left there unsolved.
I am not myself certain that it's HDR, it could just be really unfortunate and unpleasant lighting, to my eye. Regardless, the problems solved by shadows and modeling are not solved in this picture.