The understand i have is the FBI needed 200 grand. the bank supplied them with 200 grand. the serial numbers were already put on record. they supplied them with the serial numbers, but 30 grand more in serial numbers were on that list. they gave them a separate list of those numbers to remove from the original list.
The past records indicated that 250 grand was on hand for emergencies. some of the bills were not 20 dollar bills. 230 grand was in 20 dollar bills leaving 20 grand in other denominations that were removed previous to the list provided for the ransom.
$200,000 given to the FBI
$230,00 in 20 dollar bills
$20,000 in other denominations (50's, 100's etc.)
I believe the only error I can see is the two missing serial numbers from the original list provided to the public.