aa777888 - when you say 'well within' you should qualify that with 'inside the limits of the performance graphs' since you can't tell how much spare performance there might or might not be from the graph, only that you reach the max gross weight line before you hit temperature or DA limits.
Just having OGE performance isn't enough for proper confined area operations like this with tall trees - you need to have a thrust margin of at least 5% and ideally 10% to allow for the manoeuvring and any turbulence/wind shear/recirculation.
My point about the fuel - and I took the 110litre fuel capacity from the Robinson site without realising there was an aux tank giving 180 - was that to get to where they planned to refuel, they would have used quite a lot and in all likelihood got airborne from Reeds Pond in excess of gross weight. It adds to the expired medical in terms of attitude to aviation.