So why and how is it this easy to crack open a supposedly secure safe? Evidently, that "999999" code is actually the default factory code set by the manufacturer, Saflok, and the hotel just neglected to reset the administrator password (which is what they're supposed to do). By design, the safes can be opened using an administrator password in case a guest forgets the one they set, but a hotel should have changed it from the default.
It's possible that many other hotels neglect to do this, too, and that a whole bunch of Saflok brand safes around the world could be cracked with just six nines. So, before you go to lock up your precious loot next time you're traveling, walk through the above steps to confirm the electronic lockbox in your room isn't vulnerable.