Possible Cause of BPI "Data Processing" Fiasco on Double Posting: Hacking or Human Error

I used to work in the banking industry, not in BPI, and I have extensive knowledge of how banks process transactions and how to secure their systems All banks have online servers and backend processes that process "end of day" transactions, usually called batch processing I can only think of two scenarios and hacking/security breach is not one of them 1. Operator error: batch processing file was processed two or more times that resulted in the double posting of transactions 2. Test transactions done on production server that resulted in the double posting some of my friends complained about money lost while one reported her account now has billions don't worry folks, you'll get your money back if you noticed added funds, don't withdraw it as for me, I don't have much money in my 19 year old BPI account but I have sizeable amount in bank loan from them :) lastly, only someone from IT or BPI ATM Center operations knows the real issue and I doubt if it will be released to the public even if BSP comes in definitely, heads will roll in the fiasco, some already updating resumes and job vacancies to be posted soon