In "The Dark Knight", why doesn't Bruce Wayne's employee give up Wayne's true identity during a TV interview?

the joker interrupted the tv interview. the police came in and saved him so that nothing would happen. plus he was scared and didnt really know what to do, so he just didnt do anything. lucky for him, thats exactly what he needed to do, because baddd things wouldve happened if he said it was bruce. plus, the plot had to keep going...so they made the movie that way. haha (: