dervish
You need to read the AAIB report to get a picture of how the fire spread up the slopes basically much of the wreckage had landed significantly up the slope from where the fuel tanks ruptured and the impression I get is that something like a grass fire was gradually fanned up the slopes in the strong wind so the forward section had not been engulfed in flames (as some have described it) but much smoke would have been blown over it before the grass fire reached it.
While it is possible (but highly unlikely because of its mechanism) that the switch got to off on impact, it is without doubt that the STANS was still functioning up until impact; as Tucumse's query as to whether the switch being set to off stopped internal processing has not been answered, I am assuming that the switch had not been turned off by the crew the data within was meaningful right up to impact and it makes no sense that they would have switched it off anyway.
Don't worry about the switch use the miracle of the retrieved data to reconstruct the track;
it is apparent that they turned right onto a particular heading at or soon after waypoint change (HP's course selector consistent with track over ground as per retrieved data and crash position) despite that they would surely have been aware of the presence of the ground albeit difficult to judge accurately just how far it was visually they would surely have been relying upon guidance from some reference;
look at the snapshot of engine states and control positions that only fitted with their being surprised at their imminent closure with the terrain they must have been misled somehow as to how far to go;
thus far is fact evidenced by the available data;
I speculated that the only system that could have been available to them and which could explain how they could have been misled by its simply being out of position was CPLS it turned out that this system was fitted;
I speculated that US personnel were stationed nearby and would have been ideal candidates to help out with a demo/exercise using CPLS as they use the system a lot perhaps someone else was doing the ground bit, it doesn't matter at this stage.
An undeclared exercise using such equipment seems the most likely explanation and inquiry along this line should surely clear the pilots of blame a win-win situation for all of us.