Keep in mind that, IIUC, Yudkowsky got to choose his opponents. He also decided to stop playing after he lost twice in a row, as Tuxedage apparently did as well.
I don't think there is any way the AI party can win against a competitive GK party. The AI can only win against a GK party willing to role-play, and this should be fairly trivial, since according to the rules the AI party has pretty much complete control over his fictional backstory and fictional world states.
I should add that both my gatekeepers from this writeup, but particularly the last gatekeeper went in with the full intention of being as ruthless as possible and win. I did lose, so your point might be valid, but I don't think wanting to win matters as much as you think it does.
AI Box Experiment Update #3
Tuxedage (AI) vs Alexei (GK) - Gatekeeper Victory
Tuxedage (AI) vs Anonymous (GK) - Gatekeeper Victory
I have won a second game of AI box against a gatekeeper who wished to remain Anonymous.
This puts my AI Box Experiment record at 3 wins and 3 losses.