Put him and Manson in a cell and see what happens 
The more I read on spontaneous combustion the stranger it gets.
The fire starts INSIDE the body and burns outward. If indeed it is fire, the victims are all clothed at the time but sometime their shoes are left intact.
That poor guy gets high high as heck on fumes then finds himself on fire, he has the look of a man having a revaluation of some kind.