How true! It is inevitable that while being yourself via Facebook you will stumble and find yourself in that situation. What a funny scenario...reminds me of when my dad first starting using AIM and would message me while I had some unpleasant away messages up, thinking I was talking to him!
I would say that is the least of his worries though. Numerous articles are written regularly about how people have so much information posted on social networking sites that it is borderline dangerous.