After a quick public records search, it looks like he was a real person -- or a real identity with a tangible history. It appears he was formerly married to an American woman in his first marriage.
The comment isn't suggesting that he didn't exist, but rather that after he died in the motorcycle accident, it was possible to say that he was the actor and protect the people who were actually involved.
All this requires is to understand who died shortly after Stuxnet who could have feasibly been involved.
All this requires is to understand who died shortly after Stuxnet who could have feasibly been involved.