Outwest, I didn't say the crew were notified that only one pump had failed, just that it was a fact after the event.
I wasn't implying you did.
I was only asking if there is anyway the crew would know if one pump has failed (caution light, lower than normal pressure, etc) or if there is a scenario where, sometime between hour 1 and 50 of the pump drive inspection, a pump fails and the a/c departs with only one pump operating without the crew knowing it.
Not trying to stir anything or point fingers, just trying to understand the system.