NOTE: I live in Austin and am acquaintances with a few people who knew him a bit while he was here.
From what I understand, at the time of Silk Road's creation, he was not nearly technically capable of creating a site like it. He seems to have learned enough to administer and update the site, but the initial construction was done by another.
SR was just a glorified rails app, and my understanding was that it was initially pretty buggy. It's within reason that someone could pick up the knowledge they need within a few months to build such a thing, at least enough to get it rolling.
From what I understand, at the time of Silk Road's creation, he was not nearly technically capable of creating a site like it. He seems to have learned enough to administer and update the site, but the initial construction was done by another.