Many display drivers have "fake" OpenGL drivers which basically converts the OpenGL API calls to D3D, or as it seems to be in this case, DirectDraw.
None AFAIK convert OpenGL calls into D3D calls, it would be terribly hacky if it worked at all. DirectDraw however is a very different kettle of fish to D3D. 99% of graphics cards nowadays are designed to be at least DirectDraw 1.0 compliant, if not, the latest version of DirectX.
I doubt many Graphics-chip manufacturers write 2D-OpenGL drivers...
2D OpenGL drivers? :-)
Some driver designers replace opengl32.dll with their own. I've seen it occasionally.