Edit: @ Plastic Bug - It appears we have posted simultaneously. And on the same subject as well.
@Grounded101:
Most transport category aircraft I am familiar with have a panel (usually aft) for cabin crew to monitor potable water & waste tank levels. I don't believe the A330 has a cockpit annunciator for waste/water faults although the the MCDU screens can probably show status.
A VSC/LAV fault related to cabin altitude would be detected after the cabin pressurization system picked it up because the LAV system requires a much lower pressure difference to operate.
@Captain Crunch:
re: Advisory vs Warning. All of the messages other than Maintenance Status messages were either one of the two categories.
It seems a very remote possibility that the crew was completely without ATT data. Loss of air data, specifically airspeed (to a lesser degree altitude) seems to be where all of the clues are pointing.
Who knows, you could be right and if so, that would be a tough nut to crack at night over water IMC or not.
Thank you for the praise but it is undeserved on my part. It is not my sole analysis. I have assistance and will pass along the kind words. The more we look at the data, the more perplexing it becomes.