The only reason I think that Japan would have done it, is if they think that the current coup to put Hillary in power by flooding the news with propaganda about "Russian hacking" will definitely succeed, which will result in Hillary signing the TTP into law. I would rather not actually see this happen, considering how horrible the law actually is (Personally I don't like the idea of it killing the Dojinshi industry, not to mention the US jobs and jobs of whatever other modern country joins in). This was more likely a leak than a hack, considering the suspicious death of Seth Rich.