This story doesn't quite make sense. I believe that his RSA pass was clonable and that his towel also had an RFID chip embedded in it. What I find hard to believe is that the towel had a writable RFID tag.

My main experience with RFID is cloning tags onto T5557 chips, and I don't think I've ever come across a writable tag in the wild. It doesn't seem to make economic sense to spend an extra penny or two on every towel to put in a tag you are never going to change.