That we hold these late aviators in such high esteem is evident in the fact that it's taken 200+ posts to come to terms with the idea of a CFIT as a possible cause. Knee jerk reactions were aplenty, in flight break up, fuel contamination etc. Yes they may still be the cause. But also, these guys operate large machinery at very low levels, in poor visual conditions that are oft changing in unfamiliar terrain. When I looked at the topo chart I posted above, my reaction was that they had been low level, flew (climbed?) to the end of the up sloping forest (thinking it was a ridge) and maintained altitude thinking they were into another valley. It's possible they simply didn't see the gently rising grass beyond in the smoke as there was no expectation it was there.
I have never flown in smoke, but have flown in other high illusion environments. It can catch you out easily - and that's without the extra pressures that these guys face. Acknowledging that CFIT is a possibility does not take away from their professionalism, skill, dedication and sacrifice. Rather it enforces the understanding of what a damn good job these guys do in adverse high stakes dynamic situations.