i could very well be wrong, but as an old dipshit coach who got hurt his whole life i wouldnt recommend someone trying a backflip unitl they train to do it, same for a double. when i watched the turbo video (which was sick) tom is def in his early days of dubz, and its very apparent someone has taught him the technique to a dub backflip, how to tuck, pull, and spot. the fact that he stomped on a 90 foot snow jump leads me to believe that was not the first time he "set" the trick.
i could be wrong for current generation, but i remember jon showing how he trained for his new tricks and how everyone followed suit. the kids i have coached that are in x, dew and Olympic hopefulls will not be risking learning tricks on snow