Looks like he went up to FL190 and must have lost consciousness. Either he wasn't monitoring the O2 in the plane, didn't carry a oximeter, or both. Probably a low time pilot but that is a guess on my part. Not sure why you'd go to 19,000 feet for a trip that short...pwa to gtu. Not that far and these little piston aircraft are capable of gettting there but the pilots may not be. He got about halfway there and then went about 30 degrees to his left and ended up way out in the gulf. Chase planes said he was humped over and didn't respond to them in any way. Good thing he was alone. Now, maybe he had a heart attack or something else....we will never know. Similar to the Payne Stewart accident but Payne was in a pressurized jet with a couple of pilots who were riders.