Plot hole: It is never explained to the audience how Ben could fix the "incomplete" essay which would prevent him from graduating at MIT and being eligible for Harvard Med. In fact, Prof. Rosa, who was both the one who provided the initial cheating vote to the non-existent essay and then stripped it away after fighting with Ben, states that he will remedy the essay's deal only if the last trip to Vegas results in sufficient money. Then, Prof. Rosa gets kidnapped by the security guys and is never seen again.
Plot hole: After Ben loses the money and he and Mickey get into a fight, Ben talks the rest of the MIT players to risk their own money and take all of the reward instead of giving 50% of the take to Mickey. Kianna says they need at least 100 grand to play - where did they get this money from? The movie leads you to believe that Ben lost all of Mickey's money on their first night there, so they have no winnings with them. Ben's money is back in his dorm room, and you could assume the rest of them don't all have bank accounts with cash sitting in them for IRS reasons.
Answer: Casinos have always looked out for people counting cards, even before the real events that inspired this movie.
pross79