The Sanctus Phainien incorporate these servitors made by the Metier in order to fulfill missions that the Legio should not be bothered with. Once in a great while, the constant infusion of essence will develop sentience into the Clockwork. Once this occurs it is not uncommon for it to start questioning its existence.
It is also possible that during this awakening that it may loose itself in it’s newfound consciousness unaware that it will need to be keyed so that it may continue. Otherwise after it runs down, keying will only reactivate it at its default state.