Two Friends discover to see man's ashes in bathroom, and all that were left were his feet. The man Exploded?

many of my friends believe in this phenominon. the man was on the toilet at the time. im guessing it was some chemical reaction in his body that burnt him from the inside out very quickly. nothing else could've caused it. its very possible,what with all the flammable things in the human body. theres even been hundereds of cases of people exploding like this because of the chemicals messing up in their bodies. some chemicals even produce oxygen so this seems extremely plausable to me.. does anyone else agree?