One alternative possibility is that the AI's utility function will converge somewhat slowly as it's capabilities increase and it's intelligence increase. While it has not converged yet, it would behave somewhat non-perfectly, and we would consider it's behaviors to be the stochastic precedents to a convergent phase: in other words, noise.

It would then have an incentive not necessarily to conceal the general direction towards which it is headed, but instead the noise rate of it's normal responses. It could pretend to be an ethically clumsy automaton, like Koba the chimp does in Dawn of the Planet of the Apes in the scene in which he steals armament from humans.... not without killing them first.