The plot thickens.
There was an issue with the BO-105 that was similar, but in turns to the right. The crash that killed the chief test pilot of MBB is a case in point.
Not sure what it should be called - the term 'control saturation' is not one I've ever heard before (and I've been flight testing helicopters for 30 years now).
I'll see what else I can dig up on this.