Well, we might well be sleeping on the appalling fact that Kellhus came back to save Esmenet and yet didn't?
If Somnambulist is right in his reading and seemingly, at least by my rereading, he is...
If it's true, then there may be a couple of explanations.
1) Kellhus, although he could probably sense the pre-tremors of the second quake (does that sound stupid?), couldn't have known the whole thing would fall down on top of her.
2) After Kel asks her "What have you done?" he's sort of written her out, maybe? He seemed to be shunning her in some way, after he saw she'd fucked up so badly (by killing Maithanet?). Dunno.
3) She was begging him to 'just end it' or whatever. He ended it, or allowed it to end. There was some dialogue (maybe between Proyas and Kayutas) where Kayutas was saying that Esmi seemed to be Kel's weakness in terms of his perceived concessions to her. She's some kind of divergence from the Shortest Path (or something like that).
Just some random thoughts. Don't know if any of them hold water.
I'm kind of thinking some permutation of 3, because he walks away from her before the whole thing falls. Now, so, why did he walk away? Not just talk her and teleport away?
Could it be the cryptic mention of a Tear nearly missing him hindered his ability to teleport, meaning he had to talk away to do it? He could still have easily picked her up and walked away with her. But he didn't.
Then there is the whole weirdness with the repeating of her saying "Catch," a replay of when she threw the peach to him. "I let it happen" is a reference to the fact that she knew the assassin would kill her and she still allowed him in?
BTW, I felt for Thelli, too. Her's was the saddest tale to me.
Yeah, me too, because it is seemingly so senseless. Caprice for caprice's sake, almost. But not really, because we know that Inrilatas was just "heaping damnation" onto himself, his view of the Shortest Path. Still though, goes to show the power of crimes and then the great power, as we see it, of crimes against
children. She really just had no chance.