Yeah, the object is to never let the tractor and load get sliding sideways with any speed. When the downhill tire hits the slightest obstruction, the machine will rotate over and start rolling with the result you describe. Quick differential braking and throttle jabbing can keep you at an angle that is a trade-off between straight down and slightly across the bank.We have had a couple guys get banged up real good around here rolling over on hills.
We call it getting “tumble dried” (like a person being tumble dried in a clothes drier) when you roll sideways on a hill.
Understand you are only in a configuration to control a slide at that point and you will be picking up speed as the nose of the machine turns downhill. A certain amount of situational awareness concerning the weight pushing you from behind is also called for (and how it is changing the direction of the tractor).
And you will pick up speed...pick your landing strip well. And before anyone jumps all over this as unsafe...I agree it certainly can be. I absolutely do not recommend going this far. But, life is sometimes about risk and controlling outcomes... I actually am very careful when approaching and planning for these situations...
A safer way to do some of these things is simply to back up steep inclines. That has another set of problems when you don't make it.