So....if you were at a hover, two guys on the winch line, Pressure drops to zero and caution light illuminates....you hit the Red Button and cut the hoist wire, and immediately pull the Engine Lever to Stop....and shut the fuel cock to the affected engine?
That would be "Immediate" in my book.
Getting the guys at the cabin door....and transiting to Vbroc and establishing a positive rate of climb....then doing the Shutdown might work too....but is that "Immediate" enough for you?
This is not semantics....it is reality.