Gulli......if all you see is a low/zero oil pressure indication....even gauge and caution light.....how long do you spend scanning the gauges....caution panel....and other measures to determine if the indication is spurious or not?
Fifty seconds is not a very long time....depending upon what is going on....or not going on I guess.
Absent any other indications than a Gauge or Light....what does the Check List have to say?
By the time you fumble around and even find the EOP Section dealing with the problem....you will have eaten up a great deal of that fifty seconds.
Do you hurry and shutdown a good engine?
Now all this changes if there are secondary indications of a problem....like odd noises, odd vibrations, turbine wheel parts making like a buzz saw but until the Accident Report lays it all out for us....we are just having a generic discussion here.