Assuming only visual cues, the pilot could obviously find the airfield using some kind of lighting, enough to set up a left hand circuit around 05. I will also assume that he used a 'standard' 1000' Agl circuit. Using compass, watch and visual cues from the flarepath he would, I would guess, have started a turn onto a base leg at around 3 miles, with U/C and partial flap, before a turn onto final.
At this point he crashed, for whatever reason, technical, battle damage or pilot induced.
I have a limited experience of landing on grass using 'goosenecks' only, but in light aircraft. Their use for judging approach path is very similar to using electrical lighting. Although fairly dim their visibility will have been aided, in fact, by a dark night and the 'blackout', which I assume was in operation? Closer in you get an estimation of range as you can see the flicker of the flame, but he didn't get that close!
If the pilot could see the flarepath from 3 miles then it should have been obvious to him that he was too low, which would seem to rule out an altimeter setting error, leaving the aforementioned, technical malfunction, aircraft damage or a pilot error/incapacity as the cause?
I await a verbal lashing from other 'youngsters' or, hopefully, a reply from someone who 'did it for real'