Hypoxia
The recent event of a TBM700 crew falling to hypoxia (apparently) raises a question. As both a former pilot and controller I am trying to look at this from both sides. The pilot had stated a need to descend from FL280 to 180 because of some erroneous indication but there was nothing alerting the controller that the issue was pressurization. If it was pressurization why not ask for FL100? Since the pilot did not declare an emergency I don't think you can argue that the controller should have moved heaven and earth to approve 180 as requested. He undoubtedly had conflicting traffic and after he cleared the initial descent to 250 then the pilot lost consciousness.
Having said that when dealing with the insidious nature of hypoxia (I remember the chamber all too well) the pilot's judgement is impaired. I think any issue to do with pressurization needs to be dealt with a little differently because the pilots faculties come into question. How should the system be changed to address this? I find it very paradoxical but would like to hear some thoughts.