I wonder if something like this could be a factor ...
https://en.wikipedia.org/wiki/Fata_Morgana_(mirage)
The email from that Kiwi engineer reads pretty credibly so I took it seriously enough to plot his position on Google Earth and do some Googling on things that might affect perceptions of distance and how he reported that the burning stopped mid-air. I've wasted enough time on youtube to have noticed that nuclear explosions often seem to have strange light propagation effects. I googled the good old Min Min light and found the above effect. This situation while obviously uncertain, seems to at least not rule it out.
Just wondering if maybe the bearing is close but the distance isn't? The strong light of a bright fire bouncing off layers might account for the fact that the burning stopped mid air?