I know the facts from my good friend who was on board. By the way i was chief engineer, spent 30 years at sea, so have some idea what is going on during blackout. My friend did not said anything about emergency generator and i did not asked.
Two generators were ran in parallel. One stopped because of mechanical failure. They say problem was the injection pumps. The power was taken over by the second generator and got overloaded so it switched off. 450 reefers was on board, which consumes a lot. When blackout happens restarting the systems takes time, and during this period the steering gear is not working. On a smaller ship this time is short, max a minute but on so large vessel it can take few minutes.