It is VERY likely that the pilot informed the ground station that the aircraft was low on, or out of, fuel and what the intentions (attempt to ditch?) were.
How many times have were heard on this forum this type of chest thumping only for everyone to be absolutely wrong once the final report is released. Your very words are the definition of logic based upon the most dubious assumptions.
Besides, I'm highly skeptical of the idea that there was a decision to ditch. While I have never flown there it seem to me that in this isolated location I'd rather take my chances with the wind than bury the plane in the sea. I recognize that this is a "damned if you do damned if you don't" decision. But I think it's a huge assumption to make that landing on the waves would have been the better choice.
I think the much more likely situation is that she made a mistake calculating the fuel left and was either near or on her last approach when it ran out of fuel and crashed. I'm talking out of my ass, of course, but no more than Senor General.
edit: and then there is this gem:
Initial speculation, based on observations of a single eyewitness, indicates that the crash resulted from a fault in the plane’s hydraulics, a fault so great that not even the skills or noteworthy determination of Lt. Fernández could save its passengers from their fate
From the article above.