Why? Do you suspect that subjects were deliberately making their choices less random because they anticipated the poor performance of another person in assessing randomness? It seems like a good assumption that they knew they were trying to fool a sophisticated randomness test that they couldn't second-guess.
Considering that a random generator could generate 11111111111111111111111111 5 times in a row...it's a bit hard to claim someone's test results as a failure of randomness unless you claim you want a gaussian distribution or some other type of "character of randomness." Ie. running diehard tests on it and whatnot. A fixed number of trials is deceptive unless you can see the algorithm behind the numbers. And for a human being..you can't. So unless you have a giant sample size, and even when you do, there is a bit of a mischaracterization done depending on what tests you are going to use to determine how random the data is