Aaron died because he decided suicide was the best course of action. Given that the trial was what ultimately and unjustly squashed him, I would say he did die because of the harsh and unjust trial.
Depression is not a cause, is a consequence.
People suffering from depression are not rational.
I don't mean that "I can't make sense of this decision therefore they aren't rational", but people having recovered from depression consider their own thought processes from the depression to be flat out wrong.
You could literally win a lottery, and feel that the world hates you.
Your thought process would go - I won a lottery, but I still feel dead inside. Why go on, there isn't anything for live for.
I hate to use an example to explain depression, because its always "explainable", but hopefully as a vignette into what every waking moment of life is like for someone with depression, it should serve its purpose.
Edit: grammar in last para.
If you want a good description of how Clinical Depression varies wildly from 'rational depression,' read the Andrew Solomon's book The Noonday Demon. It's well written and, at least for me, expanded my perspective of how little I understood of severe depression.
http://en.wikipedia.org/wiki/The_Noonday_Demon:_An_Atlas_of_...
This qualifier undermines your point, since there was certainly evidence (as I posted upthread) that he did have a medical problem.
If you check when he started having depression and what he was reading at the time and how this depression developed you see it has to do with the way the system works, which eventually killed him.
Are you referring specifically to the JSTOR/MIT case, or to something else further back? If it's the latter, can you give a reference?
If it's the former, you are aware, aren't you, that Swartz was on record years before the JSTOR/MIT case describing his depression?
http://www.aaronsw.com/weblog/verysick
His description here sounds like the classic symptoms of chemical depression. Which is not to say, once again, that there weren't also other factors involved in the JSTOR/MIT case.
It can be both. Someone linked to a post by Aaron describing his depression; at that period it didn't seem like he had any particular stressors causing it, it was just that he was depressed. He also said that things which normally improve the mood of a person who feels down did not improve his mood. That sounds like he had a genuine medical problem.
That does not mean that his response to the pending trial was entirely irrational; but it does indicate that the pending trial was not the only factor in play.