Probably that no autopsy was done and so they are not sure exactly what killed him. He wasn't looking too good in the reports made just before he died. Pretty good reporting of the initial invasion from a grunt's eye view.
There was an autopsy done. It also seems that there were warning signs that he didn't follow up on. (see links below) Not saying that he brought this on himself but I don't understand why he is listed in this article. I'm just waiting for them to try and blame it on our troops.
Sorry to get off topic but that bit in the piece just confused me.
http://www.imdb.com/news/sb/2003-04-08
http://transcripts.cnn.com/TRANSCRIPTS/0603/08/lkl.01.html