Even something obviously incorrect can be a clue. On a 1900 census enumeration my great-grandfather's siblings indicated that their mother was born in Ohio. Every record indicated she was born in Illinois and there was no reason to doubt that. It turned out that her parents had lived for 2 or 3 years in Ohio before her birth and had been married there as well. Ohio was a clue to the family's past, it just wasn't where the ancestor was born.
Even errors can be clues, often because people remember the name of the place, but forget just how it fits into the family's individual chronology.