Continuity mistake: In the opening scene where the professor asks Ben "what can you tell me that's gonna dazzle me?" they sit in his office with a lit fireplace behind Ben, who wears a suit and tie. When that scene continues at the end of the movie with Ben answering that question, he is shown sitting in a totally different environment and outfit. (00:07:20 - 01:53:38)
Continuity mistake: In the bar birthday cake scene Cam is handed a piece of cake twice. (00:10:45)
Continuity mistake: When Ben and Jill want to leave the hotel after the chase, they are forced by Cole to leave the bag behind. When they don't agree, he reveals a gun at his belt. In the next shot, a close-up, the opened jacket and his right hand changes. (01:55:05)
Continuity mistake: When Prof. Rosa calls Cole, Terry answers the phone and places Rosa on hold. However, when Cole takes the phone from Terry, he does not take Rosa off of hold and proceeds to talk to him.
Continuity mistake: During the scene in which Ben is introduced to the card-counting group, several members are sitting at a blackjack table. There are cards on the table in front of them. In the first shot, the cards are face up, in the next, they are face down, then they appear face up again. While no one is seen or heard dealing cards, the number of cards on the table changes in several shots.
Continuity mistake: During the first meeting with Ben, the cards that Micky deals alternate from face up, face down, and missing alltogether.
Continuity mistake: The subway scenes between Jill and Ben show someone in a coat with black and white squares get on the train. However, a later scene shot throughout the subway car's window shows this same person wearing the same type of coat sitting down on a bench with a friend at the subway station as the train pulls away.
Continuity mistake: When Ben is handed his earnings from the first night a five dollar bill is seen on the outside of the bundle. Moments later a $100 is on the outside.
Answer: Gambling winnings are taxable, but using fake IDs was one way of getting around the IRS. It was also mentioned in the book that the team would keep chips until their next Vegas trip to avoid cashing out. They would also exchange money with each other so everyone would come under the $10K limit before the casino had to file a Currency Transaction Report. Also, there is no reason not to assume they would place some of their winnings as "credit" for their next visit.