TOPTOBOTTOM, There is some merit in what you post. We had a very strange set of circumstances surrounding a well respected and seemingly stable colleague who decided one day that life was just too much for him! Inexplicable.!
However, in this case I believe there is sufficient evidence (or lack of) to see DT being led down the garden path by the indications in front of him. Having said that, someone most probably switched both transfer pumps OFF during the flight!! In the end, that will most probably prove to be the root cause of this tragedy. It is no surprise that the current recommendation on seeing or hearing any fuel warning is to check the TFR pumps switches and CBs. It is simple fuel system. However, like most simple systems a "simple" simplex mistake can be catastrophic.
For these reasons I don't buy into the psychobabble theories.
Amber PUMP cautions = Pumps OFF = Supply Tanks Draining + Faulty Contents indications + Poor Confidence in the warning & cautions systems = No appropriate response from Pilot = 2 x Flameout = pressurised auto = uncontrolled descent.
It could be that the supply tanks indicated FULL throughout. It could be that despite the "Memory" in the CAD that neither the Visual or Aural warnings manifested themselves properly in the cockpit. However, for all that to happen the Transfer Pumps HAD to be switched OFF!. In my view this is the only tangible and relevant piece of information that current EC135 pilots needs to assimilate. If you leave the TRFR pumps OFF, the supply tanks will eventually run dry.
The sideshows of maintenance histories, anecdotal events of a similar nature, training, system design are all for the Sherriff to digest and decide upon.