Don't use a neural net (or variants like deep belief networks). The field has advanced quite a bit since the 60's, and since the late 80's there have been machine learning and knowledge representation structures which are human and/or auditor comprehensible, such as probabilistic graphical models. This would have to be first class types of the virtual machine which implements the AGI if you are using auditing as a confinement mechanism. But that's not really a restriction as many AI techniques are already phrased in terms of these models (including Eliezer's own TDT, for example), and others have simple adaptations.