http://dms.ntsb.gov/aviation/AccidentReports/4oomkrzfebtd5y45ic0ba0451/Y06062013120000.pdf

An autopsy was performed on the pilot by the Georgia Bureau of
Investigation Division of Forensic Sciences. The autopsy report revealed the
pilot's cause of death as injuries consistent with "blunt force trauma." In
addition, the medical examiner reported the absence of significant gross natural
disease and no focal myocardial lesions observed during internal examination.

Toxicological testing performed on the pilot by the FAA Bioaeronautical Science
Research Laboratory, Oklahoma City, Oklahoma, was negative for alcohol and
positive for an undetermined amount of Losartan, an antihypertensive medication.

Previous discussion here:
http://ozreport.com/forum/viewtopic.php?t=27909&start=53