When I listened to the audiocast, it seemed clear what he meant by "settled" the first time he used the word, and then the second usage was kind of off-the wall, wait, let me rephrase, out of left field, no never mind, anyway, it seemed like he was referring to some off-microphone exchange when he brought up the word "concrete". The effect was somewhat old-man ramble-ish, but I did not get the idea he was bringing up concrete to explain anything at all. More like he was referring to an inside joke, which is not usually a good idea. So, kind of dumb portion of the interview, but nobody speaks in public without eventually messing up. I give him a complete pass on this one.