For example, existing directories in Linux FS. Note mixed case and difference case of the two directories.
If you use the download feature of WinSCP, both directories are merged at the download destination. Such that a single directory named cherrypy contains both the source cherrypy and CherryPy directories. This is clearly and obviously a bug. At the download destination the directory structure is now corrupted given the merging.
Moreover, if you try to create CherryPy and cherrypy exists, the error reported is that directory already exists, this is clearly and obviously a symptom of the same bug as noted above.
Does no one do unit testing of WinSCP? The ignore of proper case is such a significant issue in the Windows environment, so WinSCP needs some major work it appears to honor and enforce case appropriately.