Mr. Laser Beam wrote:
I believe it was indeed TOS Spock, but he (and Nero) emerged into the past of an alternate universe. This is because of the black hole. It wasn't simple time travel, it was inter-universal travel as well. It would explain how the original timeline can continue to exist even now.
There's also precedent for travelling backwards in time into an alternate universe in In A Mirror Darkly
If there is one argument I'm willing to give credence, it's the the above.