Auto actuation of the diesel generators keep us up. The safety systems responded as designed.
Not entirely, had your diesels not started you still wouldn't have automatically tripped but ECA 0.0 would have driven you to do so.
Many plants define a LOP as Loss Of Offsite Power to Safety Related Buss's. Provided your BOP Equipment and RCPs come off of non safety buswork you can survive a LOP to the safety related busswork. I know my plant is designed that way.
My old plant depended on exactly which train you lost but in any event would have either Automatically tripped or would have been forced to trip.