Other than "Do you have any questions for me?" my interviews tend to stay on-topic too. Of course, I'm the bottom interviewer out of an entire command chain, so they probably all run into the usual bullshit somewhere along the line.
Getting feedback from the candidate is just polite, I think, and you usually glean more information from the questions they ask than the ones you do. The rest of those stock questions are more or less designed to help out managers who aren't exactly clear on what they're looking for - they tend to gravitate to whoever does the best job of telling it to them. The absence of all that is a good sign, since they apparently have a skillset they're looking for, already know from your CV that you can fit into it, and just needed you there for a few minutes to verify that you don't smell like a used mop and can string two sentences together without stammering.