I got flamed for mentioning this previously in this thread but for those in the know, they understand where I am coming from. It may be a language issue:
This particular pilot hadn't done an EOL auto for possibly decades.
In his time prior to becoming a police pilot (UK) he flew Chinooks. I believe (stand corrected) he flew them for 13 years?
Chinook pilots don't practice switching all engines off and having to physically fly tons of inert metal down onto the ground. In fact 'almost' all mil pilots no longer exercise this luxury - it's too expensive to train like this in the event of a mistake.
Then he joined the police (maybe AS355) and flew the Ec135 twin.
NO police pilots fly EOL's to land.
Almost ALL mil and police pilots practice autos (and my definition of an auto is bringing both engines back to FI, flying the profile and then recovering to a set minimum height with both engines constantly 'on tap' throughout ANY mishandling of Nr during the descent. It is an OK process, captures most issues, most of the time. BUT it is not the same as a proper E.O. descent where all engines are removed from flight and unavailable throughout - Nr takes on a totally different trajectory. Lose it below Nrmin at your peril.
I think - overall, David was not only shocked/surprised when both donks stopped (the silence must have been very spooky, possibly frightening) but when Nr then went walk about on a spectrum he was unfamiliar with - he didnt have time left to 'get accustomed' to an old regime he probably saw and recognised 20+ years ago.
Add to that no rad alt or L lamp, wet rooftops and road surfaces and before you know it - Nr< 60-70. Goodbye Vienna.