Dark Mail is written by someone who was convicted of helping to steal credit card information?!
In theory, but realistically very little FOSS is audited, and audits are not perfect (and we have to trust the auditor). We have to trust the authors.
Not only that, but when he was being pressured and threatened by the government, he refused to cooperate. I think that's commendable and demonstrates real integrity.
Unless there were logs or talks of them doing it for purely academic/educational purposes, which as we know Gonzalez isn't that "sort" of person, it would be unacceptable to think someone of Watt's intellect wouldn't be able to put 2-and-2 together.
He's been around the scene. He knows the scene. He's been a part of the scene.
I agree in terms of law, this all goes into a very grey and fuzzy area - if he had a better lawyer he may have came out in a different situation. Looking at the recent backlash for hackers, he may be looking at an apology (or even a payout) in the future.