According to American Justice TV show, it was rigged and had at least 2 players that won big money and confessed this on TV later on. One man was mad because another contestant won more than him. When he called them out on this, along with the fact that he was promised to be hired as a regular, their answer was, "We knew nothing about such a promise.
Another possible of likely fraud was the fact that right when the show was loosing viewers(due to the contestants who found the questions too difficult to answer) these 2 contestants ended in a tie, which attracted people to continue watching. On that particular show, he was scripted to give the wrong answer.This one contestant told everything, including being scripted to act nervous as though he was trying to remember such as biting his lip, and patting his forehead as though he was sweating profusely, when in fact he knew all the answers in advance. The other contestant didn't confess to anything accept the show was rigged.