like it's entirely possible he couldn't hold on to the bag/satchel/whatever, that they brought him the money in, to the plane. He had no method apparently of attaching whatever type of bag... he wanted a napsack, to wear, but he didn't get that. It sounds like it's entirely possible he lost the bag in mid jump, due to the wind speed and not being able to hang on to it. Which lends itself well to two more things: one, the amount of money washed up and eventually found on the banks of the river, and two, if he lost his $200k bounty, that lends itself to his desire to do it again to make up for the loss, thus the later "copycat" hijacking that ultimately got him arrested, and put in jail. Then he escapes, and ends up getting shot and killed by the FBI. It seems all very plausible, that he couldn't hang on to the original "bag" and lost it mid jump.