If your network is exposed to hackers then you have bugs in your network. What kind of bs are they trying to pull by saying " these were not bugs; it was information about how our products work." If they worked then you wouldn't be in trouble for being exposed.
On the other hand. Extortion is bad, if that's what they were doing then they should face appropriate action. But using the DMCA in this was is still just as irrisponsible as it was before this response.