On a Lynx RR Gem engine, it was widely known that from the point the oil pressure went into the red (stepped gauge, red, amber green) the white metal bearings at the high speed input end would seize within 30 seconds followed by a loud bang as things went badly wrong.
Why anyone wants to keep an engine, that would be spinning at many thousands of rpm, going for any longer than it takes to confirm a double indication (gauge plus caption or noise) I really don't know - this has become a very semantic argument about definitions and exact timings. The quicker you act (once positively diagnosed and confirmed) the more likely you are to prevent further drama.
If you have a double indication, that should be enough to determine it isn't spurious and, even if it does somehow turn out to be, what is the drama with a precautionary shutdown of one engine in a twin?
If the oil light comes on in your car, how long do you keep driving it until you stop for a look? Do you assume it is spurious and then wonder why you end up with a garage bill for a new engine or rebuild?