We just experienced a classic situation that shows why Windows' overcomplicated ACL and permission system is hardly usable in real life situation.
Windows apologists always complain that Linux's simple user/group and rwx permission system is too simple to match the complex situations you will find in real life. Well, sometimes it is problematic to project complex real life relationships of project teams, people and objects that need access control to Linux. But the clue is: Windows isn't able to do that, either. Why? Simply because it doesn't work reliably.
Now back to the "classic" example that I mentioned above: a colleague opened an SMB share to let me copy a few files from him. I was able to access that share, but when I clicked through the folders to get to that file, I was stuck at that point. "Hey, that folder doesn't even exist!", I told him, but for him, they were visible. He checked and double-checked everything, he even had permissions set to "allow everything for everybody" (0777 in Linux jargon) on one of the root folders including the "children inherit permissions from parent" option. Well, it worked for all files, except for the one damn folder that I needed to access! I even logged in as "Administrator", so Windows just behaves mysteriously.
My guess is that the folder's name ("docu") is a registered keyword such special situations, but that sounds too weird to be true. Anyway, I managed to get the file by simply trying to enter the folder name in the Windows Explorer's address bar, and that worked! Crazy. Really crazy. I'm already looking forward to the times where I can again use any other OS than Windows at work.