I don't remember him explicitly writing that the info was for educational purposes. Most of the information released was through posts through a public forum like this. Also, but not 100% sure but pretty sure, that the site was on US servers, which doesn't help much either.
Now on the other hand with D3 reversing, they (dev's of main d3 server emulator) haven't received a C&D yet and they have explicitly written that it is all for educational use. (
http://mooege.org). However they haven't posted actual documentation regarding the bnet2.0 auth like rob was doing, which is probably why.
But I really don't know what makes blizzard pissy without being part of their legal team. I can just speculate, but speculate quite well though.