The post doesn't go into enough detail to be sure, but I think the "asshole" participants fighting for control of the whiteboard assumed that whoever would successfully lead the group to solve the puzzle would receive good marks and have the highest probability of receiving an offer. Furthermore, some companies, or departments/teams within companies, foster a corporate culture where "assholes" are more likely to be promoted. So a group participant who isn't naturally an "asshole" may have taken a risk by behaving like one, gambling on the idea that such traits would be looked upon favorably.