This is what happened in the game. It was between Kim Seong-ryong 9-dan and Weon Seong-chin 6-dan (Black) in one of the leagues of the 1st KPI Cup in June 2005. Black won.
Wang Xi says this sort of play is hardly ever seen in Japanese go, but it is the normal way for Koreans to play.
The Japanese, he points out, would play Black A, White B, Black C. He does not elaborate on this point, but it is true that you would probably have to go back to the days of Sakata Eio to see the daring kind of second-line move typified by Black 3.
Wang does not say so, but the Japanese are fully aware of their own style of play
and have a name for it. They call it souba 
go. It's a fairly common word in go texts, but has probably never made any impression
on a western audience because it is difficult to translate in a consistent way.
The basic meaning is 'market price'. The idea is that a player, in a situation where it is difficult to assess the long-term outcome, will compromise and take whatever is clearly on offer. It does not necessarily mean slack play, but it does put the fatal moment off and leads to longer games where endgame skill can tell. To keep the stock market analogy, you might say that they try to win on arbitrage. The longer time limits prevalent in Japanese go probably have something to do with this. Historically there seems to be a connection between endgame skill and time limits such that pros will nearly always opt for an endgame contest if they are given enough time.
The Japanese pros are currently taking a fresh look at the merits of souba go. Since there is pressure also to move towards shorter time limits, we can probably expect to see a change of style soon.