He's tiny. Theres a photo of him next to Bill Clinton.
Yes, he's lean, probably around 8-9% bf. He is tiny regardless. If you need to be under 10% to have "good abs" your genetics either screwed you or you have very little muscle. My perspective is of course skewed from my past in sports at the collegiate level. 6' 185-195 11-13% bf is what I consider average amongst my peers
And always, people as short as he will always appear small