Art, not "at Dalkeith", but en route from Dalkeith to Bothwell. If working, the display should have shown diminishing fuel, and this should have been diminishing main tank until empty. Any deviation from this is obviously wrong. You cannot postulate any fault condition which would make this happen.
Against this is the necessity to wear nvg because of the lack of cultural illumination on that leg, but to say that nvg affect safety would be to negate the very existence of the 135T2.