So The Open Group have certified that OS X is compliant with SUS V3 and Apple have the right to use the UNIX trademark in respect to the OS and you say it is not UNIX...forgive me for not being convinced that it is not UNIX.
"really? hmmm... didn't know that. what is it then?"
It's a Unix-like operating system. I believe there is a group that is working towards compliance with SUS V3.