Depending on what file system is used file names may be case sensitive or case insensitive
AFIK, this is not true.
Let me explain:
Can you have two files, having the same name just differing in case in the same folder under linux? (I can't test at the moment but I think you can't)
Under windows you can't.
So I don't think a situation can occur where two different files differ only in their name case (one being small the other large capital letters or a combination) and are in the same folder .
Therefore, if my assumptions are correct, it should be safe to compare with out case sensitive comparison.