With no experience at all I would have thought the drill could be set up in a cage as a computer-driven tunnel boring machine would be, to work the 20 hours instead of some unfortunate propping it up that length of time.
I only hope he was adequately recompensed. Maybe 1% of the dignitaries annual income.
Still, it shows one should never build a defence too difficult to be breached in an emergency.
Also: apart from terrorists and advertisers desperate to seize control of the Internet, it is unlikely the average burglar would seek the contents of the safe.