Before someone asks: person one was very much also taking part as a participant and not an actor. We discussed our confusion at the experiment over a drink (both of us had just made €50.. Serious money for a student in the early 2000s).
edit: I answer some other questions in the comments. This was in a university of Groningen building in mid 2002. That's unfortunately all info I can find (I really just participated in these things for the free lunch and small compensation..).