Because I've been on both ends of the interviews and I've seen places where a handful of unplanned questions and comments have gotten useful information and oth

Because I've been on both ends of the interviews and I've seen places where a handful of unplanned questions and comments have gotten useful information and other interviews where no on-the-fly questions were asked and I think it was a missed opportunity. If you were to apply no true Scotsman to what is considered informal you might not include this because it was useful but I'd rather not do that.