I asked the same thing at first, and it doesn't. In fact all of this was extremely confusing until I figured out the technique, which personally I feel should not be named after the author as this is one that has been in use for a very long time.
50mm f/1.2 - a lens most photographers know extremely well. Up close, amazingly sharp DOF that looks beautiful. From a distance however, the DOF is much more lack luster ( as that is how lenses work). Now for you to get the shot desired by this lens (up close, yet the entire scene) you just couldn't.
Instead the author takes multiple shots and stitches them together to keep that super sharp up close DOF, and also get the desired distance from the subject. The entire calculator that says the end image is "27mm @f/.44" is bull, it is creating an equivalence from a panorama -_- at the end of the day it is a stitch. That is just to get an idea of what would be needed however, should you want a lens capable of doing what this technique does.
**Edit**
To add to the conversation however - I feel the author doesn't use this to its full advantage. Working in small environments we used to do this in school to capture large sets where our actors were very close to us and we simply couldn't back up any more. Although we did 2x2 instead of 4x4 patterning (believe he stated he uses 16 shots).
I think this technique really shines when you have an actualy set up shot, instead of just regular people. Then again I also lean towards the more photoshop heavy side of phtoography lol so I can't really comment on that.