I always felt he pulled it off.
Almost pulled it off.
My theory is this: He made the jump OK but lost the money on the way down. That’s why the money has never been found except for the decaying stack of bills found near a river a few years ago.
I also believe the best suspect was Richard McCoy who was caught and convicted of an identical hijacking only a few months after this one. This time the money was found in McCoys house.
McCoy later excaped from prison, went on a crime spree and was eventually killed in a shootout with police all the while claiming his innocence in the Cooper case.