I just thought of something else.
When Jack and Locke give Ben (Henry) some cereal, Ben starts asking them questions about the Hatch and where the food came from and where the Hatch came from and ends with the comment (I'm paraphrasing here), "With of you don't know about this place, you don't seem very curious about finding out more."
Do you think he was referring to the hidden hatch under the computer banks where the Failsafe was hidden?
The hatch they never found in all the time they were pushing those buttons?
And the Failsafe Key that Desmond left behind in that book. They never found that, either.