How Did Cooper Strike the Flake Crew?

Cooper ordered bourbon and soda, he paid for it and even tried to give the change to the stewardess. He also offered to have meals brought in for the flight crew while they were on the ground so they wouldn't be hungry once they took off again. The fact he had insisted on four parachutes, two primary ones and two reserve shotes was clever because it meant they couldn't rig the shotes. How thoughtful cooper was has contributed to his legend. Did the authorities try to rig the money they were getting? To get him the 200 thousand dollars he demand, they got ten thousand 20 dollar bills. They didn't mark the bills, but they did take photos of them