You mean "splutter and cough" like the cliche aeroplane in the movies?
It's not gonna happen in a chopper. Planes have the prop attached to the engine, which keeps the engine turning if it momentarily stops, and it might encourage the engine to fire up again and keep running, albeit for a short time. Hence the "Brrrrrtt .... brrrrrttttt...." of the movie engine failure. It also doesn't matter if the prop is forced to stop because the engine has siezed.
A chopper has the freewheel unit, which prevents the engine being driven by the rotor, so if it decides to suddenly stop, the only thing that will make it kick over again is you releasing the collective and turning the ignition key again. And that ain't gonna happen.
So, there probably will not be much sputtering, just one burp and it's gone.
And if Whirly can't get the throttle into the detent, how does she teach going for range in autos, pulling the revs down? Or controlling the revs in a turn during a 180?