I know nothing about the tech aspects of the DECU...
However, a glider pilot friend of mine was killed when the aircraft she was flying lost its tailplane..
As a qualified parachutist, she would have stood a chance of survival had the aircraft not gone into an unrecoverable situation.
My point here ?
She was a very experienced pilot, had numerous gliding achievements under her belt, lots of hours as P1, she had carried out AF/BF checks on the aircraft all was found to be in order. The tail separated some 15-20mins into her flight.. !!
The relevance is metal fatigue/vibration can take affect when you least expect it to !!
Sadly, if this DECu was known to be faulty then the negligence in my book is with Messrs W & D, SofS, MOD PE for allowing an aircraft into service with known defects that were not corrected.
SF Crew = Scapegoats !!