i actually use to do that a lot. The stock tires on my 04 r1 sucked. It was slightly diff because he is doing it while breaking basicly shifting weight to the front.. when i did it was coming out of the corner on the gas the tire would slowly just drift out.. If you knwo what you are doing and a bike is set up right its no big deal . Ive had some people witness me do it. You just kinda become one with the bike after a while.