kind of dancing around the real issue here. You get a high temp alarm on an engine, you do a few things immediately:
1. Reduce power
2. Shut it down
3. Go in the er and check things out.
If there is a fire in the exhaust fg tubes, if you catch it early it can be put out with a handheld fe. With engine shut down, if internals are on fire, it will quickly be starved of air. Engine idling, plenty of air.
I also doubt the scenario is as published: Ntsb states that diesel exhaust can be 400-1100f. Yep, at power. Most at power run below 900f. At idle, there is little heat coming out the exhaust, maybe 300f. If engine is left idling with jacket water boiled out, it will go higher, but no where near 1100f. I suspect he remained at power for a while after the problem began and that is what started the fire.
So now we have them proposing numerous regulations regarding fire suppression, maintenance requirements, sight tubes with automatic valves, etc.
But the cap't was an idiot, and that is the root cause. Get an alarm, shut down the engine!! I don't know a single cap't that does not know that is the drill. Then go in er and check things out. There was presumably other crew that could do that or take the helm while the cap't did.
Sea water pumps can fail five minute or five years after an impeller replacement. A new govt reg requiring a maintenance schedule does not change that reality. How an operator handles the failure is what determines the outcome.
The cap't might have had a license, but did not know how to operate his boat.