Could he be further back?  His shins are almost perpendicular!  Depth is coming, as this weight still isn’t enough (somehow) to force him down, and trust me he is relaxing to get deeper, which is kinda nuts.

Also, the astounding man core is critical.  According to Dan Atchison, David’s "Ab" is beautiful.  Even though our man David is down 8lbs since starting Paleo – fantastic!