When an experienced pilot crashes a fully functioning aircraft in broadly benign conditions there is commonly an issue of cognitive psychology in play. In other words, some 'software bug' of the human mind or perception from which none of us can ever be entirely immune. I remember a phrase from my psychology degree: 'we are free to construe but bound by our constructions'. In other words, you can make sense of things in any number of ways, but once you have made sense of things it can be inherently difficult to step back and identify mistaken assumptions. This can be a vicious trap in an emergency situation, where perception is narrowed and time is short.
In other words, it's worth considering whether the pilot became cognitively disoriented. That need not mean spatially disoriented. There are plenty of examples of crews intensely working a puzzling but irrelevant problem until CFIT, or becoming increasingly exasperated by 'spurious' cockpit warnings until the tragic moment when those alarms prove to have been functioning exactly as intended. The answer to 'But in that situation, every pilot knows to...' may lie in figuring 'What could possibly have somehow led him to doubt or be in denial that he was in that situation, just for long enough to no longer be within the recovery envelope'.