I was looking at Simple proof that GUID is not unique recently. It's funny as hell, and I especially liked the person's response of selling cheap China GUIDs. But no one seemed to answer the fellow's question.
I believe his test program can prove a GUID is not unique if he combines it with a VM rollback attack. The rollback need not occur by an adversary - it could be an operator who inadvertently rolls back to a previous state.
For the "me too" voters below: please pay attention to the details. I did not ask how to re-open a question. My only concern is to have a correct answer added to a closed question. I could not care less if the question is re-opened (or not). Please control your imagination.
How does one have an answer added to a closed question?