I think we have different ideas about the meaning of responsibility. I don't care much for responsibility in the "who is the one who we should blame" sense. I prefer responsibility in the "what can we do to prevent this in the future" sense. Saying "he could have not hung himself" is not a complete or particularly effective solution. The prosecution being overzealous, the laws being unjust, and MIT taking a poor stance on the issue... these are the problems that can be solved. Those are the people who can be "responsible" for preventing similar needless tragedy in the future.