My ATM Card

I was browsing through my ATM transaction slips when I remember that sometime ago, in the year 2004 to be exact, something happened to my ATM card while I was away.

My ex-husband and I were still together then. We went to Cebu for a vacation. We left my house and my car to the care of my ex-brother-in-law (my ex-husband's youngest brother). I did not realize then that my LBP ATM card fell from my bag while I was in the car right before we departed for Cebu.

Upon our return to Butuan, I was relieved when I found that my ATM card was at the passenger seat of my car. To my surprise, my account balance was decreased by P1000 (don't laugh. P1000 was still A LOT then). I then inquired from LBP-Butuan. That ever gracious staff (thanks to her) revealed that indeed there was a cash withdrawal made from my account at the LBP-Butuan ATM machine... WHILE I WAS IN CEBU.

So, who was the culprit? I then remember that weeks ago before that incident, I oftentimes requested my ex-brother-in-law to withdraw money from my account. Hence, he knew my ATM PIN. And nobody knew my ATM PIN, not even my ex-husband (as I don't trust him that much), except me and my ex-brother-in-law.

So, to repeat the question, who was the culprit?