No games in Fritz DB with blacks 2nd move

This interesting game, played last evening at a club tournament, was against one of the clubs virile young upstarts.

A fritz database classified it: A04, Unusual lines after Nf3, & Kings Indian Defence; and strangely, found no games in the DB with blacks second move b6.
I think it is a notable example of "shooting from the hip" type countplay to an opponent opening.

I saw the skewer coming but decided to 'just let it happen' with satifying results... Who wins the exchange?