I've just accessed the open data index site. It's great to have NGOs be critical of governments; that's what some NGOs do, and I welcome their constructive criticism. I have no idea about their methodology. I'm going to click on “contributors” to see who contributes to this organization. There are a number of editors from around the world. I don't know who they are or what their credentials are, but I'd be happy to delve deeper into this site that you seem to be quoting.
All I can tell you is that we are part of a 60-nation partnership. We are proud to be leaders in this field, and we will continue to be.