and the lab discovered they made a mathematical error. >> i immediately realized i made an error in calculating the initial concentration in randy thompson's blood and it was off by a factor of ten. when we made the appropriate correction for the mathematical error that i made, it suddenly became a lethal level. >> i've been doing this for almost 20 years now. this is the first time that such a mistake has ever been brought to my attention. >> the medical examiner now knew that randy thompson's death was a homicide. >> based on the corrected toxicology report, it was quite obvious that mr. thompson died as a consequence of an acute intoxication or poisoning. >> when i found out randy died from antifreeze poisoning, i knew when they exhumed glen's