Obviously there will be variables in both a 'leakage' and a 'pump failure' scenario. The fact that the Bypass needs to be operated within 5 seconds of the MGP OIL PRESS warning indicates the kind of worst case leakage rate that SAC envision - which is rapid, but not instant - but there could be lower rates of loss and it is my belief that these would register as pressure drops too, based on my experience of the type. Similarly, it is true to say that some pump failure modes may show instability initially, but once the drive fails the pressure drop will be pretty much instant.