We acquired R22’s for a commercial school back when there was no prohibition on demonstration of the low G’ roll of phenomenon. It was apparent that you had to push over for a significant time before the roll off occurred. It is not a instant occurrence. Thereafter the instructors demonstrated the low ‘G’ problem, the correct recovery and the students practised it, dual only of course. I think that this was a better policy than the build up of the myth and legend since the prohibition.
I always thought that a more likely scenario for unexplained R22 accidents was lack of attention to correct carb heating technique. Unfortunately carb heat assist doesn’t guarantee no carb icing as you need carb heat BEFORE power is reduced. Carb icing is disguised by the governor until the engine stops. Then you have to lower the lever damned quick, If you don’t, the rotor rpm decay is very rapid, followed by rotor stall and blow back. I think that this is more of a hazard than low ‘G’ mast bumping.
Roll off occurs even slower in the R44 and slower still in the B206, but it can happen as it can to all gimbal head helicoprers