I had one like that and I did get the callback. We were basically just shooting the *&^% about their firm and other various topics, like how much I enjoy golfing even though I'm a terrible golfer. I think one of the partners is a terrible golfer who loves the sport as well. I think interviews are often a test of whether or not you'll "fit in" because what little qualifications you have (GPA, class rank) speak for themselves. In other words, they probably did have their minds made up before the interview, but if they were going to give you the callback originally and didn't like you after the interview, you won't get the callback. Instead, some other person who they weren't originally going to give the callback to will get it (assuming they like or, at least, do not dislike that candidate).