How and why: After clinching his Olympic gold Shaun White racked up even more points with a Double McTwist

How and why: After clinching his Olympic gold Shaun White racked up even more points with a Double McTwist. Part two: The 23-year-old American successfully defended his title in the men's halfpipe event at the Winter Olympics - and then topped off with a move that requires immense technical skill. [Correction added 23 February 2010: The text below is incorrect. Shaun White won gold with his first