Since we have raised several new questions and ideas about how to make things better....lets return to what brought us here at this thread.
We know there was a confirmation by the Crew they were seeing "Zero Oil Pressure" an reported to ATC while on descent to 800 feet.
We know they had a two way conversation with OPS and can only assume they relayed that situation during that conversation.
If we accept the fact they did in fact continue to see "zero" oil pressure we have to question why they did not carry out the actions dictated by the checklist.
"Zero" oil pressure is one of the confirming situations that kicks off the instruction to "Land Immediately".
If the decision was made because of confusing indications....say an oil pressure that was flucuating above 5 PSI then we might suspect they might see a way out of the situation. Given the choice of ditching or continuing to fly I am sure most of us would see any indication above 5 PSI in a postive light and probably discount the fact the majority of the indications were under 5 PSI. That might not be the smart view but when confronted with ditching or not we would probably want to avoid ditching.
If the decision was an improper diagnosis by them or someone in OPS that caused them to continue flight then that would be a tragedy but seems a remote possibility.
If the decision was to avoid ditching due to the sea state and the knowledge of how cold and rough the water was and they accepted they had a very serious gearbox problem but they or someone in OPS decided it was best to try for land then that raises more questions.