Não é trapaça, mas em partes, concordo com o roy nisso:
The logic behind it is that him having more incentive or action increase his motivation and affects the outcome of the bet. Yesterday he was ready to give up. What if today some hypothetical leprechaun came and bet him $1,000,000 to his $10k? Of course he would take it, and do whatever was in his power to win the bet. And that is unfair to the original betters who believed that his maximum incentive was $50k (to his 25k) and that that was an amount that he might be okay "giving up" for, thus winning them the bet.
edit: óbvio, considerando que o urubu não vai usar terceiros pra pegar action. Levando-se em consideração que se o urubu fosse pegar, seria diretamente, sem terceiros. Mas realmente não tem como evitar que terceiros peguem por ele.