Tell that to Marquez, Vinales, Rossi, pretty much everyone in the MotoGP paddock except Lorenzo lol.
In my limited experience about getting the rear end loose,its happened to me under hard down shifting and letting out the clutch, the motor will slow the wheel enough for it to skid a second while the wheel speed and motor catch back up to each other. For me, its accidental and has only happened 1 or 2 times. For them, its part of their riding style. @hiro
Slipper clutches are supposed to help this issue. I've never had one to play around with.