One can only obtain the full range of a Zande's ideas about causation by allowing him to fill in the gaps himself, otherwise one will be led astray by linguistic conventions. He tells you 'So-and-so was bewitched and killed himself' or even simply that 'So-and-so was killed by witchcraft'. But he is telling you the ultimate cause of his death and not the secondary causes.
You can ask him 'How did he kill himself?' and he will tell you that he committed suicide by hanging himself from the branch of a tree. You can also ask 'Why did he kill himself?' and he will tell you that it was because he was angry with his brothers. The Cause of his death was hanging from a tree, and the cause of his hanging from a tree was his anger with his brothers. If you then ask a Zande why he should say that the man was bewitched if he committed suicide on account of his anger with his brothers, he will tell you that only crazy people commit suicide, and that if everyone who was angry with his brothers committed suicide there would soon be no people left in the world, and that if this man had not been bewitched he would not have done what he did do. If you persevere and ask why witchcraft caused the man to kill himself the Zande will reply that he supposes someone hated him, and if you ask him why someone hated him your informant will tell you that such is the nature of men.

(E. E. Evans-Pritchard "Witchcraft, Oracles, and Magic among the Azande")