OP mentions it briefly, it's not clear how much detail was brought out about this. Most people are concentrating on making a "good impression" and won't say something like... I am working on X which I expend to spend 20 hours a week on, what do you think about that?
If it's as implied and they flat lied in the interview then change policy? Step 1 is ignore them, you're not doing anything illegal. Step 2 is find a new job immediately.
