One - I noticed a bit of a production oopsie. In the final scene in the mental hospital, when they're showing definitively that Dave isn't real and that Libby was there, you can still see the side of Dave's shirt before the cut to the shot of Hurley with his arm around nothing.
Two - I think a lot of people were too focused on being religiously offended by the line about God not being able to see the island to notice that that scene was probably really, really freakin' important. Henry seems, from the references to "him" in the interrogation scene with Sayid, to be in the same Dharma-Others group as Ethan, Goodwin, and Mr. Friendly. Why, then, is he saying what he's saying about the hatch, which appears to have been constructed by Dharma? "This place is a joke"? "Your vents ... your computer"? Either he's playing with Locke some more or there's something really big that we don't know yet about this.
Despite whatever he says to contrary ("I am done lying"), Henry has told only lies. Why would this be different? My thought is that either Henry concedes to himself that he will die one way or the other, so letting the computer run it's course without inputting the numbers will take everyone out with him. OR, he is hopeful that not inputting the numbers will lead to some sort of Others reconaissance team sent to the hatch to input them, and therefore find and save Henry.
Yeah, I don't see why Fauxhenry would have told Locke that he didn't input the numbers when he really did. Unless he was trying to get Locke and the others to give up and leave the hatch. This seems extremely unlikely to me, as the hatch has only been a source of grief for the survivors, in my opinion. So I think Fauxhenry was telling the truth. But I do NOT think he is necessarily done lying.
And his saying that "God can't see this place"... I think that was either an extremely important clue, or Fauxhenry has simply just given up.