Objective metrics is always a challenge as it requires a common unit of measurement.
Turbulence that significantly reduces the G below 1 or leaves you feeling light in your seat would be a good place to start.
Not a good place to be with a Robinson rotor head.
The fact is that Robby's have limits. You can either accept those limits and have a happy career, or you can ignore them and die
But only the Robbie has had them added to (reduced speed envelope) following a series of accidents and a great deal of pressure from concerned aviators.
As you come to acknowledge your own limitations - as I suspect many of us older types here have - it is reasonable to question those of the machine as well rather than assuming that everyone who hasn't crashed in a Robbie is awesome and those that have, brought it on themselves.