One more thing…
If it was all a lie, what was all the fuss about? Why was the Doctor so convinced that his death was necessary and inevitable and that his “time had come”? Yeah he was feeling old and useless, but like I said, the Doctor having to fake his own death is a much easier problem than having to actually die, and there was no reason for him to be all that fixated on it at all.
However you spin it, the fact that the solution came as “Oh, well, since you mentioned it, Mr. Tesselecta Captain, I guess you could help me avoid death” is just lame and undramatic. There was no sense that he had to work up the determination to fight against time itself or anything like that. The solution (and even if the Tesselecta hadn’t offered, I have to think there were tons of ways he could have faked his own death) was within his grasp all along. He just had to decide that, you know, he didn’t feel suicidal after all.
All of this is made much worse, IMO, by the fact that Moffatt actually went to the trouble of setting up a genuine, non-cheating, non-deus-ex-machina solution to all this. More than one in fact. First, he had the Ganger Doctor, who was established as being just as much the “real” Doctor as, you know, the real Doctor. They also established with Amy that a Ganger could replace someone for quite some time, even without the person themself being aware of it. The Doctor could easily have been a Ganger for the whole season without knowing it, so that when he died, it was really the character we’d been following all year. It would also have added poignancy to the Doctor’s decision to kill Ganger Amy if it was revealed that that Doctor was himself a Ganger who would have to die for the sake of his other self.
Then there was the whole thing about Old Amy being “killed,” and the Doctor saying she was “not real” even as she cried and suffered and railed against the dying of the light. What if the Doctor had to create an alternate timeline in which he died. What if it was in fact the “other” Doctor who lived, the one we hadn’t been following? Would he feel as cavalier about letting someone die because they weren’t “real” when it was his own ox being gored, or would he have some sort of epiphany that gave him a redemption from that (rather disturbing) moment earlier in the season?
Compared to either of those endings, the ha-ha-it-wasn’t-me-it-was-a-robot-and-btw-I-was-never-in-any-real-danger-I-just-wasn’t-sure-I-felt-like-living-anymore-and-was-going-to-let-them-win-but-now-I-feel-better ending that we got … well, it just sucks donkey balls, frankly.