I'm slightly surprised to report a 100% score. However, I think I'm actually recognising DALL-E-2's _style_, and not "this picture is CG". It feels more like I'm identifying the work of an artist I'm very familiar with, rather than identifying fundamentally different categories of creator.
I think all it would take to "defeat" me here would be greater variety of high-quality image generation AIs.
I expect in a few years that will be the case, unless the "style" of DALL-E-2 is something fundamental, instead of an artifact of its specific implementation.