But a mistake would show up on the fuel gauge in the cockpit.
Btw, all this semantic discussion about fuel related helicopter accidents.... The cause of this tragic one may not be fuel starvation.
Agreed that there is as yet no evidence in our possession to suggest that the cause was fuel-related. Certainly something went wrong. The a/c wasn't intended to crash onto a city pub seemingly with no power being transmitted from the engines to the rotor.
Was the pilot incapacitated? Has not been stated either way.
Did the pilot make a flying mistake that he failed to rectify?
Was the aircraft wholly or partly un-flyable? (e.g. fuel, mechanical failure)
It is possible that the cause is included in all of the above.
For example, the pilot was under the influence of some substance and took off with less fuel than he thought. Concentrating on the mission, believing he had 'plenty' of fuel, he didn't focus on the fuel. When the fuel warning came on, some distance from base, he was taken by surprise and became disoriented, perhaps due to the drugs. The pilot commenced a manoeuvre in an uncoordinated manner losing altitude to the point that he considered that to land on the apparently safe black block below him was a safer strategy than recovery and return to base.
There is no evidence whatsoever to support that or rule it out....at least not evidence available to PPruNe posters. Furthermore, it seems unlikely given the service record of the pilot. Until some other hard information comes to light, we haven't got anything more to go on.