It really depends on what you consider extroversion, I really think that if he was extroverted it would probably appear on his pictures. Think twice, ponder about the subject. If he was EXTREMELY extroverted, it would probably be something remarkable even in his pictures, what is clearly not, in every single picture of him he is, what I would say, kind of EXTREMELY feeble.
I'll try to read more on him, than I will post my conclusions on the theme... But I find "ENTj" a typing that is really hard to be true, he simply doesn't seem to fit to the archetype, neither the niche of this type.