Surely dumping the collective will have a higher success rate? As I recall, the 'tip over angle' is smaller for a loaded disc (because the lift acts through a point higher than the CofG), and therefore means that it will never tip over in the other direction with the collective lowered. Especially so, when you consider the damping effect of the landing gear. It would seem to me that the quicker you lower the collective the better chance you have. I've also considered the option of yawing into the roll, but I think if it got to that stage it would be too late anyway.