A WhyDunnit

Sometimes a mystery story is referred to as a "whodunnit", as the tale is about the discovery of who "done" the crime at hand.

More recently, the word "howdunnit" has been used for those telling where the reader knows, often from the beginning, who has committed the crime – but has to figure out "how" the authorities are going to solve the mystery or catch the criminal.

I don't know if the word has been coined yet, but the position below, from the game MyGameUMove - BanditMan, blitz, FICS, 2011 (a Blackburne Shilling Jerome Gambit), seems to be an example of a "whydunnit".

The game has just seen 21.c4+ Kd4, and at that point Black, rated about 650 points higher than his opponent, disconnected, forfeiting the game.

Why?

Black has two pieces for White's three extra pawns, which seems like an advantage. His King is remarkably safe, despite all appearances. Perhaps time was an issue. Perhaps he received an important phone call.