Original Message

 really think 'rolling off' was instantly available in the 135, or was it an ENG switch thing?

I.e. your idea seems not at all probable.  What the pilot did seem to do successfully is fly the thing right to the scene, aka appears he may have never given up, at all.

Irrespective of what prompted the scenario, even if it involves the pilots actions that precipitated the ugliness, the causes of all this will be very interesting.