No good deed...
... goes unpunished.
Although it would be easy to say that it's his own fault for running something which can be abused, I find it difficult to do so.
He was providing his own resources for the benefit of others. Of course there is the potential for abuse, but it is a sad state of affairs when he is punished for doing a good deed. I have heard of other cases which have had similar effects, e.g. people hosting public Wi-Fi APs etc. being collared when it was someone abusing their generosity. Hell, our office has locked down our "visitors" Wi-Fi network because someone was bringing their laptop in and downloading torrents, which almost caused the entire companies internet access to be cut off.
It reminds me of a school friend's hippie mother. She tried to help people out wherever she could. At one point, she started allowing (through a charity) homeless people to stay at her house. She had a spare room, and they would stay for a few days, get hot meals, showers and a nice warm place to sleep for a few days. She got nothing back except the knowledge that she had helped someone in need.
This all stopped after one person abused the system. Someone who she had been so kind to robbed the house (and the insurance wouldn't cover it).
It is abuses like this which stop people from helping. It makes the whole world worse off. If I was this guy, I'd be very reluctant to run a Tor exit node again, and the story will likely put others off from doing the same. It makes me sad (although the cynic in me knows that this is just how the world works, I always try to listen to the ever-diminishing voice of my inner optimist)