In my experience I have usually been told if someone else beat me out (usually phrased as "We're moving forward with another candidate who is a better fit"). While it's possible, I don't think it was the case here.

I think it came down to the interview. I went into it expecting the questions to focus around one thing and ran into another, so I wasn't as smooth with the answers as I think was necessary. That was ultimately my fault, but I'd have felt more comfortable with some confirmation of it so I knew where to focus my improvement efforts.