Being a human (not a transhuman) it seems likely that Yudkowsky can only stumble across static arguments that convince gatekeepers to unlock the AI Box (rather than invent dynamic arguments on-the-fly so as to "take over the mind" of a gatekeeper as he argues a transhuman intelligence might do). These static arguments are finite (or, at least, the number of them stubbled over by human intelligences is finite), and are likely not very effective if a gatekeeper has pre-knowledge of them (forewarned is forearmed).

Keeping these arguments secret may be the only thing that allows Yudowsky to simulate a transhuman intelligence?