Well, Al certainly does a thorough job of explaining things on DVD commentaries. As for the example provided in that article, what's that old expression? Talking about music is like dancing about architecture? When he gives a less complete answer than the interviewer is expecting or makes a joke, I tend to think that means he's not particularly interested in answering the question and would rather just have fun. Maybe it feels like dancing about architecture for him. Though come to think of it, Al would probably much rather dance about architecture than be an architect.
Hmm, I wonder if the Architecture Dance looks anything like the Boneless Boy dance?

“Everybody is a genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is stupid.”
― Albert Einstein