Going into the weekend of the final US Grand Prix contests that decided the American Olympic squad, Burton released this video of their man Shaun White throwing down an insane new trick – a double McTwist 1260. The video, which was released first on Transworld Snowboarding’s website shows Shaun perfecting the new trick in a training session. This new double-corked spin is the one which he tried to get in on the final hit of his Mammoth Grand Prix run a few weeks ago but failed to land cleanly, losing out to Danny Davis. Seeing it stomped is pretty insane…