It's not the case here (I think), but this can be common if you move functions around or expose functions that were previously internal. For example, maybe you

It's not the case here (I think), but this can be common if you move functions around or expose functions that were previously internal. For example, maybe your function is only called from another one that performs the appropriate bound checks, so checking again becomes redundant. After a simple refactoring, you can end up exposing your function, and screw up.