I don't think he claimed ignorance. He said he knew it was illegal and had a lapse of judgment, IIRC. To me, that reason is far, far worse than being ignorant.

But like I said, this is all from memory. I'm guessing that a concerted Google search would provide definitive answers.

B

PS In his defense (logical, not legal) classifying his notes "Top Secret" was the problem. I bet he knew that was a dumb classification -- on par with cryptography and nuclear weapons design. So given the predisposition that the classification process is hopelessly flawed, it is easy to imagine rationalizing removing the docs from the facility. Not saying it is justified, but I believe it is understandable--not either treasonous nor insane.