He may have been a victim of partial tyranny. I say partial because I believe he had other options and the idea that one's name has as much value as he gave it is something of his own making.
Most everyone faces obstacles in life. We all have to choose how we deal with it. For me personally, violence is a poor choice, and against an innocent, not one I'd ever make. If he had only chosen violence against those who were 'responsible' than that might be a little different. Ultimately, though, he seems to actually hope to accomplish some good. I think he will find that his choice just won't do it, so he probably should have chosen a different path.
Also, he seemed to have cast a pretty wide net in terms of who was culpable. A lot of those people, to me, just seemed like fairly ordinary humans.
Whatever he was, and even if we agree that many other forces brought him to that point, the final step was his and his alone, which means he is now a victim only of his own choices.
Of course this pretty speculative. A manifesto and a few news stories doesn't really get deep into the man.