On Mac OS X systems, if a file system is not specified as case sensitive then some matches will fail to detect issues. Perhaps a function will need to be implemented to resolve this situation. A test could be performed to check if a directory exists by changing directory into the directory and checking for an error exit code.
Essentially, rsync will be case sensitive. However, the bash test statement for a directory on a Mac OS X system may not be relied upon for case sensitivity.
if [ -d ./myFile.txt ] ; then echo "hello" ; fi
The above code will return hello even if the case sensitivity is not a match on some Mac OS X systems.
Suggestions to this issue are very welcome.