Define "Immediately" and "Prompt", please.
Folks keep using that word....Gulli said 30 seconds until an engine goes Kaboom but has not offered any basis for that.
No one is objecting to shutting an engine down if it is believed to be without adequate oil pressure or in fact has zero oil pressure.
The discussion is how does one determine if the indications are not spurious and how long do you allow to determine your plan of action prior to actually shutting down the ailing engine.
Explain your thinking about all that.