Welcome to the land of Hindsight Bias. Enjoy your stay.
What on earth are you trying to say? There is no instance of hindsight bias here.
I think he's saying that your statement "I'd gain all of the money for a start" only works if you knew that Nick was going to "split".
You know that in hindsight, but you wouldn't have known it at the time.
I found this to be a very interesting method of dealing with a modified Prisoner's Dilemma. In this situation, if both players cooperate they split a cash prize, but if one defects he gets the entire prize. The difference from the normal prisoner's dilemma is that if both defect, neither gets anything, so a player gains nothing by defecting if he knows his opponent will defect; he merely has the option to hurt him out of spite. Watch and see how one player deals with this.
http://www.youtube.com/watch?v=S0qjK3TWZE8