That gatekeeper isn't very security minded. They should have their IRC on a client that pings a sound when they hear your response, then paste "AI DESTROYED" and hit enter to send the message without actually reading your response, and without TELLING anyone that they are doing that, (Gatekeeper wins all rule disputes, after all.) and then once they hear the outgoing text, and they've destroyed you (and hence won.) THEN they can read the text you sent them, if they are curious.
Those rules seem like they force the gatekeeper to read at least 1 sentence, but they don't actually do that.
Edit: Better method, set up a script that responds to any and all text with "AI DESTROYED" if you have to wait for the person to start typing, they may try to bore you into opening your eyes wondering why the experiment hasn't started yet, and you might accidentally read something. Again, tell no one you have written such a script and are using it.
The gatekeeper is supposed to be someone who thinks they can box a superintelligence, remember? If they refuse to risk it, there's not much point in playing them.
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.