That was one of the issues Walker answered. He said medical experts said it is possible for a man to take that much because if taken in a gradual build up, your body will be able to tolerate more and hence, the need for higher doses in order to feel an effect.
I had gall bladder-liver surgery. I busted my left eye like a grape resulting in 1 regular and 4 laser surgeries. I've spent 18 years doing various types of carpenter work-construction, and have had several minor injuries such as 3 nails going in my knee. While using an air staple gun, one prong of an 1 1/2" staple hit a knot and came out of the top of the wood right through the middle of my middle finger. And then there's my dirt bike accident.
Point being, I have at one time or another, taken the following pain medicine; liquid demerol and morphine, lortab, vicodin, darvocet, percodan, tylox, tylenol 3 and 4, and oxycontin. By far, oxycontin is the most potent pain killer in a pill form I have ever taken.