Gee, could it have been that his wife and family released a statement that indicated 'natural causes'?
Do you really think that the WH had him killed and then contacted the media, instructing them to say 'natural causes'? Sheesh.
Ever hear of operation Mockingbird?
I’m not saying anyone killed him, but for the sake of argument, if someone killed him and made it look like a heart attack or used a drug to cause a heart attack, how would his wife know?