You are probably aware of the existance of chkbfs. This tool checks the file system for errors, and corrects them, if possible.
Nothing is perfect, so you might not even be asking yourself why a journaling file system comes with such a tool.
In fact, it wasn't originally included or planned in the first releases of the new BFS file system. It was added because there is a real need for this tool and you are advised to run it after having experienced some BeOS crashes.
