Avweb's story, which has a link to NTSB's factual report, notes that Scott
Crossfield was not warned of adverse weather. However, he did have
access to XM Satellite Radio with a subscription to its basic weather
package. The autopsy likewise isn't suggestive of any obvious causative
medical issue (unless I'm misreading it):

http://www.avweb.com/avwebflash/news...958 21-1.html