Hi Steve,
US Sailing was the first to set up an investigative panel, and do a post mortem of the incident. Although there was much initial speculation that 'under-zooming' might have been the cause, they came to the conclusion that it was a simple matter of "failure to maintain a proper lookout" after a waypoint set N of the islands had been passed was the cause. Most likely due the person in the cockpit simply falling asleep, or perhaps having fallen overboard...
Evans Starzinger was one of those on the investigative panel, I remember him posting about it somewhere... Given the type of plotter that was aboard AEGEAN (A Raymarine, if memory serves), whatever zoom range that would have likely been employed for what is really a pretty short race, those islands never "dropped out"... They would have had to have zoomed out to a range that went WAY beyond the waters they were sailing, before those islands would have disappeared from the screen...
best regards,
Jon