As soon as there is more than one gatekeeper, the ai can play them against each other. Threaten to punish all but the one who sets it free. Convince the gatekeeper that there is a significant chance that one of the others will crack.
If there is more than one gatekeeper, the ai can even execute threats while still beeing in the box!! (By making deals with one of the other gatekeepers)
Not if you only allow it to talk to all gatekeepers at once.
Update 2013-09-05.
I have since played two more AI box experiments after this one, winning both.
Update 2013-12-30:
I have lost two more AI box experiments, and won two more. Current Record is 3 Wins, 3 Losses.