Jim,
Please note: "he could probably throw it nearly as far"
"Nearly" doesn't do the difference justice. Draw a line on the ground. Throw one ball standing still (hell, take a step back and then forward if you want) and another with a run up to the line. You'll throw it so much farther with the second one it'll be a joke.
The assistance the "Happy" run up gives to the kinetic chain is what we're seeing. There's no "secret" we're all missing here.