Can't you read? Do you not understand basic English?
Russell Harding pointed out that there was a possibility that it COULD be done... not that it was being done or had been done... so Apple made it so it couldn't be done.
Was it a threat? Only in the sense that any thing not thought of could be a potential threat in the future. Was it a vulnerability? Yes, if you don't trust the Administrator level users on your own Mac... but then if they have physical access and administrator permissions on your Mac they can do ANYTHING including activate Root if you haven't already locked it out with your own secret password. Was it ever exploited? NO.
It would NOT have been a threat to 99.9999% of Mac users.
You're a joke and the sad thing is you don't even know it.
An hole allowing an exploit is BAD! You see when windows does that and patches it before anything is in the wild Windows gets a black eye. But when Mac does it...the answer is the handful of Mac users are protected because apple has fixed a security hole. However, since nothing was released in the wild this doesn't count as a security vulnerability.
Whatever. When you learn how to use logic and reason feel free to resopnd. Until then I'm done (for now).