All the "heavy" stuff (it isn't that heavy) bolts to the case. The only thing that goes on the shaft is the disk itself. 
I don't think he's referring to the weight of the components.
The driveshaft e-brake holds the weight of the vehicle.
In two wheel drive, with the brake set, all the energy from the weight of the vehicle trying to roll downhill, is transferred as torque on the components inline. I would imagine all the force is distributed from the contact points, tires, to the point of restriction, the e-brake itself.
So tires, wheels, axles, diff assembly, u-joint, driveline, u-joint, to rear output flange. At that point I would think the mounting points of the e-brake bracket take the next point of torque. If the disk and pads are clamped tight, I don't see how force could be applied to any point in the driveline...in two wheel drive.
In four wheel drive, the force from the front wheels back to the e-brake would transfer torque, caused by resistance, to all components invloved...from the tires to the e-brake.
So then, from the front tires, birf's, axles, diff assembly, u-joint, driveline, u-joint, output shaft, bearings, gears, rear ouput shaft, e-brake.
I think that's what HR81 was referring to. I could be wrong.
