Odd that Section 31 was so thorough in one time, and so completely inept in the other.
How do we know that they're inept?
Kirk and crew finds them on accident in 2267, but S31 finds them deliberately, presumably several years before 2255-6? It just strikes me as odd.
I thought it was future Spock that let it be known too, but I guess that doesn't make much sense either if Harrison is supposed to be a tenured agent.