I don't argue for or against that 'new algorithm', just the topic we are talking about. Nevertheless, I haven't seen a proof that voxels can't be rendered more efficiently (although I think it's very improbable), while infinite compressibility is easy to prove to be impossible.

Edit: You didn't clearly get what is claimed here. 'Infinite detail' is just a marketing speech, the claim is that the algorithm can render up to screen resolution any data set whose size is limited only by memory. I.e. rendering speed isn't bounded by the size of the data set. The method has nothing to do with compression, and indeed the data set will be huge if everything is 'infinitely' detailed.