I think it's very weird, when it was first in the news earlier this week the assumption was he'd been dead for months and why hadn't he decomposed, now it's the other extreme. Very peculiar story.
Insects greatly aid the decomposing process. They are attracted to the smell of a cadavar, and they will eat the body. In the middle of an ocean, thousands of miles from land, there are no insects within range to detect the dead body and eat on it.