What a sad event.
Having read about considerations of loss of lubrication of the main transmission (though I am certainly not speculating, because I know nothing of this event) I am reminded of the concerns of a similar nature associated with the fixed wing LearFan of the early '80's. That aircraft had two engines driving one propeller, so it's intended redundancy of powerplants were considered in the context of a helicopter.
The gearbox design, included a block of wax within, which would melt at a suitably high temperature after oil loss for whatever reason. Cast into the wax were spring loaded electrical contacts, which closed once the wax melted. The closed contacts told the pilot that the gearbox was now being lubricated by the wax, and down would be good.
I hope we learn a lesson, which makes the cost seem, in the slightest way, bearable.
Pilot DAR