The way he did it was, Step 1: Make low poly Low Poly Step 2: Import to zBrush Step 3: Sculpt details, (while retaining the overall shape) Step 4: Then bake maps using the low poly from step 1.
Yup, it's an interesting process ! Especially since it bypasses the retopo step, reduces the amount of required sculpting and also forces one to focus on the bigger shapes. From the (very little) experience I've had of it, it basically allows one to cut straight to the chase. The one downside I could see is that it might…