@Mad Mike
You've touched on the important point here - What he did was not right, i.e. it was wrong.
This is why the systems being down are attributed to him. Had he been a pen tester, then yes, the downtime would have happened, but and this is critical would have happened in a planned way at a time those responsible believed to be reasonable.
I'm not saying it's fair that the blame for this lays at his door, but it is an obvious indirect consequence when pissing about on someone elses network.
I agree that they are in fact shooting the messenger, but that's exactly what you should expect to happen when you are doing wrong. He didn't knock on the door and politely tell them, he kicked his way through the (in this case unlocked) door and left a note.
I'd say there's a certain amount of embarassement at higher levels which Gary is unfortunately paying the price for, again it's not fair but it's a position that can be legally justified.
If it helps, think about it as though it were a business. An unscheduled outage could cost the business a lot of money, a scheduled outage will be planned to minimise that. What Gary 'caused' is the former wherehas any repairs resulting from a pen testers report would generally fall under the latter.
Both sides have fucked up, the DoD should have taken security far, far, far more seriously and Gary should never have gone poking around in the first place. The simple fact is though, two fuck-ups do not make a right and complaining about that outages that occurred as a result of his actions shows nothing but a naive view of how the world actually works.
All that said, I'll say again - I don't think he should be extradited. He was in the UK, so they should try him here especially given the precedents others have referenced. That doesn't however change the fact that the allegations are more or less exactly what I would expect to be levied in these or similar circumstances. It's incredibly simple - if you are doing wrong, don't be surprised when indirect consequences are added to the list (you brought them to light whilst doing wrong, so they will be blamed on you).