I bought a sky HDR, and wanted to duplicate the environment I had set up using a free sample of it so that I wouldn't have to copy the settings over to it. So I duplicated the environment, changed the texture to point to the high-res HDR, and BOTH copies updated. Duplicate is supposed to make copies not instances, and there is no "Remove Instancing" available to 'unlink' them.
I can't repeat that here - duplicate always creates a separate instance. And if the objects really are instanced, then the "Remove Instancing" command on the menu should be active.
Yeah, funny, I just tried it again(new instance of Rhino)and it didn't happen. It definitely did yesterday.