If that is the case it would seem that a specific decision was made to not evacuate for some reason rather than indecision and that the decision was passed to the rear crew.
Or no information/order from the cockpit.
If we back up to the start, they turned back beacuse of ? Some say oil leak, some say fuel leak.
Both should normally lead to an engine shut down. They descended to FL 170, and that is an indication of an engine shut down.
My check list then says: Land at nearest suitable airport. This flight flew past a number of airports suitable for a 777. Unless the weather was crap at all of them, that was not a good decision, and in violation of SOP for a twin with one engine out.
Fuel dumping with an engine shut down and a possible fuel leak?
If the leak was contained, I don't see why not. If the leak was not contained? Not something I would do.
Now, lets throw something out there. The way this fire acted/spread, wouldn't it be a possible indication the fuel dump was forgotten, and fuel dumping was done all the way down to touchdown?
What puzzles me is how the fuel (leak or dump) was ignited.
A long landing indicates not so hot brakes. Was the right engine running and triggered the fire?
Did they fly with both engines running, a fuel leak and dumping fuel at the same time?