Impossible to know what the pilot was thinking...reporting one hour endurance just before running the tank dry. Maybe the engine going quiet the moment it did came as a surprise. I mean, if you know you're about to run out of gas, having the ability to safely land a helicopter anywhere it would fit would be a very appealing option. Rather than running it dry and ending up somewhere where it doesn't fit. Not much thinking going on I suspect, especially in the planning before the flight. No excuse for departing with less than a full tank of gas.