It could easily be true. I've read several biographies where big game hunters had seen baboons rip through people's arms and tearing them so pieces. If there are enough baboons they can kill full grown leopards.
About the witchcraft, I know someone who works for TEHIP (medical organization) in Tanzania. They have a huge problem with parents who instead of bringing their children who have malaria to their centre's will take them to witch doctors. They may also pee on them (to lower the body temerature), but they don't actually know why that helps.