If a helicopter effectively runs out of fuel. Or indeed the fuel is mismanaged such that does not reach the engines, the sole responsibility for this rests with the authorised Flight Crew. The Pilot(s).
However, to accept that happened in this case we have to accept that this pilot flew on. Past the point when the helicopter gave clear warning of impending doom. The other crew may well have been aware of those warnings but they will generally follow and support the pilot in his actions, sometimes even when those actions are flawed. This also happens up front, between two trained pilots when one is assigned as the clear leader. It is a very complex and difficult phenomenon. A few promising and otherwise competant co-pilots have had their careers cut tragically short, often posthumously, for this very reason.
Overexposure to the onset of the hazardous condition. Risky Shift. Is one explanation for this. In the case of this accident it may be that the crew were reasonably familiar with flying with low fuel warnings with fuel clearly in the wrong place, such that on this night nothing seemed overly wrong until the first engine flamed out.
Our only protection from these conditions is strict adherence and compliance to the rules, regulations and operating requirements. In this case, despite the fact that system knowledge may have been poor, there were two clear safety break points afforded by compliance. The onset of MLA and the Red Low Fuel Warnings. Both conditions requiring a fundamental response from the pilot that would in both cases have avoided this accident.
In my view this is the lesson and the legacy we take from this accident.
DB