Africans are so backward and lazy that a lot of black women are eaten by crocodiles, when they could be saved by spending a bit of effort, but it’s to much trouble.
Actually that's not the reason. There is a belief that crocodiles that attack people are sort of reptilian were-wolves. Witch doctors transform themselves into crocs to get even with people who have harmed them. Now if I have never offended a witch doctor, the were-croc would not want to get me, right? If the croc gets me after all, why then everyone knows I was lying about not harming the witch doctor.
BTW: "spirit medium" is a better translation than "witch doctor."