Okay, yeah, Keltham would not have gone straight to 'something from Outside' all on his own, at this point. But even without Ione prompting him, Keltham would have noticed that this wasn't adding up.
"If you pull down an asteroid that's massive enough and fast enough to shatter a moon on impact - a reasonable civilization wouldn't expect to survive that impact in the first place, that's not the kind of calculation that's easy to screw up if you can redirect asteroids at all. And also you wouldn't expect the asteroid to have a core piece left over that turned people into gods when they touched it. And the whole thing sounds like maybe agents weren't choosing optimally, which makes it sound prophecy-shattering, which you wouldn't expect random asteroids to be. You can imagine entities from Outside sending in something like, an uplifter. Or maybe a poisoned gift, a Starstone that uplifts cooperative civilizations that will eventually trade with you, who'll be grateful for the help, but if the local civilization starts fighting over the Starstone instead of just using it on everyone, it's also very easy to weaponize - we've got a whole subsection of literature about that, how aliens might send us gifts cleverly meant to destroy us -"
"Sorry, going depth-first again. What's known about the larger universe that includes Outer Gods and not just, it sounds like maybe this whole local region of reality is inside a bubble that Pharasma is maintaining?"