Gatefan, think of it as being like a job interview (which this was, really).
At an interview, you are judged before, during and after the thing. Did you show up on time, did you dress appropriately, did you give an appropriate greeting, did you answer questions, ask questions, etc.
And then, you are judged by how the interview ends. Did you keep on topic and avoid personal stuff? A lot of employers don't really want or care to know about your personal bits, and can and do veto an otherwise excellent prospect based on those last few bits of information they receive. If you head out the door with a "Go Niners!" and the hiring manager is a Ravens fan, you may well have just screwed up your potential employment.
Really.
BINGO!
A business meeting lasts the entire time you are there with them. You have to adhere to professional conduct that whole time because you are an ambassador of your organization whether the talk is business or not.