Yes, I know this post is a month gone, but I wanna put my two cents in. 
When you are discussing something in a private, two-person conversation, you tend to give answers that you think of, instead of just agreeing with what one of your friends say (often just because they are your friend).
Plus, and booga_ooga noted, it's easier to improvise your questions suited to the specific interviewee based on the answers they give to other answers. 
[Note: a lot of my answers were not as well thought out as they could have been, because I was trying to catch as much as I could of the new InuYasha episode. >.< Darn you, hateful!]