@Unblinking
The thing is, read literally, the ending implies that T. was destined to die for the gods, and nothing he did could change that. He thought he had escaped, but he couldn't, because the gods required him to be sacrificed. Thus, when he didn't go to the knife willingly, they blew him out the airlock and into the atmosphere. However, if we take as a given that the gods' will is supreme and no one can escape the fate laid out for them, then the whole "changing history" thing makes even less sense than usual, since the gods could just have given the Aztecs a leg up in the first place and didn't even need to go down the wrong leg in the Trousers of Time in the first place. (Ignoring the whole paradox that traveling back in time to fix a problem removes the impetus for going back to fix the problem.)
I mean, I liked the story, but I really do hate time travel. I'm okay with a little bit of "You Cannot Escape Fate," but when the whole story is ABOUT someone changing not just their fate but the fate of the whole world, the usual "But nothing he did mattered because he was Fated" ending meshes really terribly.
However, hallucinations from oxygen deprivation are definitely within the realm not just of the plausible but the probable, so that's what I'm going with. Bah humbug.