solarbird | Late Friday action in equities

This isn't a real entry, but I was wondering wtf was up with Friday's close in the equities markets - that was a gigantic spike out of nowhere, and confusing to everyone. Karl Denninger has a theory; "Someone was forcibly liquidated out of a short position - a fairly big one. 1,000 S&P 'big' contracts has a maintenance margin requirement of $22,500,000 - that's not a small position, and each point, as noted, has a $250,000 move associated with it. Who was it and why?" He outlines his theory as to that.