Before you can solve a problem, you need to know what THE problem is. In this case (as usual) a lot of contributing factors were a fact, but not THE problem.
So, what was the problem???? The pilot(s) went below flight-idle, THAT is the problem! Why?? High, close, fast etc....
But why did they go below flight-idle?? Fokker issued a bulletin about this many years ago (after the klc-crash at ams...), warning the pilots!!
And there IS some kind of a detent on the flight-idle setting (and nothing wrong with flight-idle in-flight, you can even select Go-around on the ERP so the props act like speedbrakes).
Sounds like a "get-home-itis" to me, and therefor defenitely piloterror!
My thoughts go to all the family involved!