I don't know it could be just a plain excuse that the machine malfunctioned since they had time to make an excuse and use their own TOS to get away with paying the said jackpot. Maybe the woman can file a complaint against the casino or even check if the machine is faulty or not, but who knows what could've they done to the machine after she won since she was asked to return the next day. In case the machine is faulty, everything in their casino should be checked since they will always use this excuse to avoid paying winnings.