In the appendix of that Futuremark report, the screen caps are rendered so badly, it looks more like serious driver bugs than cheating. Why were Futuremark so sure it's not bad drivers or some other technical fault? Malice vs. incompetence etc.
They state that those rendering errors are only visible when using free-camera mode, not the standard pre-defined camera. That's why it looks buggy, it was never "optimized" to look well outside of the benchmark's default camera settings.
They also point out that preventing NVIDIA drivers from detecting 3DMark results in the scene being rendered correctly.
If these claims are true NVIDIA can't shift the blame to some incompetent programmer.
Here is one report from Futuremark themselves (makers of 3DMark): http://www.futuremark.com/pressroom/companypdfs/3dmark03_aud...
More recent PhysX cheating: http://www.theinquirer.net/inquirer/news/1048824/nvidia-chea...