The rules were certainly unclear on that point. Mike didn't guarantee to preserve the file metadata. It seems eminently defensible for him to say that he was d

The rules were certainly unclear on that point. Mike didn't guarantee to preserve the file metadata. It seems eminently defensible for him to say that he was dealing in files, not filesystems, so he could rename the file upon receipt. In fact, the EOF-hack in Craig's solution turned on the assumption that the filesystem could be hacked by the challengee, so it seems fair to allow the challenger to hack the filesystem as well.