only happened once in the whole fleet
This for sure if that only happen once in the whole fleet. But if you consider all accidnents and also all incidents reported and unreported the the case could be different.
If these kind of identified risks will be e.g. in automotive industry the reactions and the actions will be different. I have been earlier naive that in the aviation the safety is always the first.
I'm counting on the NCAA and Nigerian AIB that they will dig it out what is the root case. My tip is to condider the Mixing Units design "it really mixing the helicopter's controllability if any malfuntions happen in the helicopters's flight controls system".
More than 700 units of S76 still flying and the most likely this 3rd February, 2016 accident is not the last one (related the loss of helicopter controllability). I hope that I'm wrong.