Oh wait, they know what Tom Ogle overdosed on, I found this paragraph from an article about the inventor:
"Ogle had been gravitating toward gambling at the pool table, and began losing a lot of money in his gambling forays. He indicated to his attorney, Bobby Perel, that he believed people were drugging his drinks. Perel was skeptical, but on August 19, 1981, Ogle collapsed and died from what an autopsy showed was an overdose of Darvon and alcohol. The death was ruled to be a suicide after a cursory investigation, but several people close to Ogle indicated that they did not believe that Ogle would or could kill himself."
From:
http://www.io.com/~maniac/environ.html