SASless: are you familiar with the opposite problems in HUMS, false positives? My experience (about 2 decades ago) with a much older version of a system like the HUMS was plagued by that. I am not sure what the current state of play is with HUMS and various similar systems, but let's not pretend that it offers omniscience.
Look at the human factor here: if a given HUMS type of system is low confidence as perceived by the people using it, then there is ample opportunity for their frustration with such a system to believe that yet another false positive has confronted them.
Not saying that this is the case regarding this incident, nor the previous loss in Norway, but it's a human factor that should not be swept under the rug.