That would explain how he built it in a cave with spare parts wouldn't it. You find a patent attorney and I'll head to the local pick-a-part and we will be in business.
The Boston Dynamics walkers are fairly magnificent, but they howl like one of the Zanti Misfits piped over a P.A. system. You can even try to push them over and the software / balance protocols allow them to remain upright. Of course making all of that noise they are useless for any military application which requires stealth - the enemy could hear it coming a mile away - so you might as well use a chopper, an air-drop or some sort of loud supercharged all-terrain vehicle to bring in supplies/ammo 'cause the enemy will know exactly where you are anyway with all of that infernal howling.
High-voltage, lightweight portable power supplies for robots are like caseless ammunition or nuclear fusion - everybody talks about them being on the horizon but they never quite emerge from pipe-dreams into the real world. The problem is any time you pack a lot of power into a very small package it becomes high risk for things like massive explosions, fires or emission of deadly radiation.