The muffin didn’t cause his death
Another person could eat the other half of muffin and be fine.
Nevertheless, he wouldn’t have died if he hadn’t eaten half the muffin
And he did it on purpose.
Did he consume anything else apart from the muffin?
Is whatever killed him still in the room?
Was any animal involved in his death?
He wanted to suicide. He selected a toxin that he couldn’t tolerate alone so he baked muffins to make it palatable. He didn’t know how much toxin it would take to kill him so he put toxin in each muffin. He buttered all three in case he needed to eat all three. Turns out it took just one half of one muffin.
Was poison the cause of his death?
Was traumatic injury the cause of his death?
Was a burn of some sort the cause of his death?
Would knowledge of the composition/recipe of the muffins be relevant to solving the puzzle?
You got it all right, but I would simply clarify that he could have died without eating half the muffin. I wouldn’t worry about it, it’s a stickler point, but not a big one.
Aha, so he was shot. Now we just need to figure out why, and what the muffins had to do with anything.
Did he shoot himself?
Did he own the muffins?
Did the shooter recognize him as the owner of the muffins?
If the shooter did not know that he had eaten (part of) a muffin, would he have died?
So far, the best I’ve got is that he wanted to die, so he deliberately antagonized someone by eating their muffins, with the expectation that this would cause the muffin-owner to shoot him.
Is his motivation for committing suicide relevant?
Did the medical condition have an impact on his motivation (e.g. he committed suicide because he was depressed, or just didn’t want to live with his condition any more)?
Did it have an impact on the WAY he committed suicide?
Might a person without this condition have also committed suicide under similar circumstances?
Would such a person have eaten half a muffin first?
Was the man a diabetic?
Was he depressed?
Did he have an eating disorder?
Did he resolve to test his restraint by placing muffins in front of him but forbidding himself to eat them, to shoot himself if he gave in?
Was the man alone when he shot himself?
Did eating the muffin somehow make suicide a better experience for the man?
Was the butter used for another purpose besides being spread on the muffin?
Did the muffin contain something?
If so, did the man find it after taking a bite?
Theory: somebody put a bullet in the muffin and the guy was in a jail cell, deciding that suicide was better than his eventual punishment.