Did you actually try watching your card after that conversation? I had a similar experience a few years back with a guy at a tech meetup who casually showed everyone how to clone RFID badges. It really woke me up to how sloppy our security can be. What worked for me was switching to a separate card just for online and tap payments, one that I keep a low balance on most of the time. That way even if someone did get the info they wouldnt get much. I also started using one of those RFID blocking sleeves for my wallet when I travel. It is not perfect but it adds a layer of trouble for anyone trying to skim my stuff.