I often wonder whether modern advanced battle systems might be more easily disabled as they have more complex and delicate sensors, etc. but this is on a different level. Not sure if any ship is designed to survive this but a total power failure disabling comms (and thus modes of restoring control) seems to be a weak point here.

As always, communication and coordination are crucial, so they should have been prepared to fall back to older comm methods (the "runners" manually carrying messages). With the steering gear still working, this might have changed the outcome of the incident.

Naval vessels carries spare hardware for all that sort of stuff and "we've taken a hit in the <pick some compartments> the comms/power/water/steam/hydraulic line is severed, run the spares, fight the fires" is a fairly standard drill.