[apricot]

I don't buy it. The FBI found his code sheet that he made, and tracked him down, and asked people about him. This is an investigation, and it's about him. The fact that they thought he was a Japanese spy simply means that they made the wrong assumption about the person they were investigating.

[albrewer]

The investigation was about the document, not the person. If, after they had met with the guy, they started interviewing family, friends, and digging into his life - THAT would constitute an affirmative answer to the question.