I don't fully understand, the official Google Reader logo looks exactly like the "unofficial" logo, so did Google copy the "unofficial" logo or was it a copy of Google's? This isn't addressed in the blog post.
The official logo came first and is the more "blocky" or "3D" of the two. The author created his version later, which somehow got picked up as the "official" logo according to Wikipedia. Thus news sites started using this "official" logo believing Wikipedia albeit incorrect.
I'm not a lawyer, but the author's image is in fact a derivative work of the original, and as such I'm not sure there's much he can do in this case. If it were an entirely unique creation that was being used without permission you'd have more options.
Did the Google version definitely come first? Looking through Google Reader blog, all I'm seeing is the textual "Google Reader Labs" logo with the chemistry beaker, until the 3D one appears in a desktop widget in May 2009. The OP's Flicker page is date June 2008. Anyone have earlier examples of the Google version?
My version was based on Google's 16x16 favicon. It was basically a scaled up version of that. Their "blocky" version did exist before, but mine was specifically a take on their favicon.
