he wasnt interviewed extensively. he most likely couldn't even enter the ark until after the horn toppled, due to the massive battle. he also was probably carried up until the final moments before arriving near the throne room. like i said he was being held down by a skin spy until after kellhus/godtime which is where he hears his father and wants to exclaim his excitement
I don't think the battle would have been an issue. I don't remember when the scene occurs where the skin-spy takes him in (whether the battle was organizing or in full swing). However, we know from prior events (from what I recall of the Nau-Cayuti dream where Seswatha and he break into the Ark) that there are other subterranean entrances to the Ark. As well as the vast passages previously excavated to encircle the first Ordeal. He very well could have entered earlier on.
Now, given when he was likely brought in not long before the events that followed, I doubt there was time an extensive interview. But given his words 'I told you, I told you!', well, it seemed very likely the Mutilated at least somewhat interviewed him. I don't think the claim (POV>conjecture) holds much wait because you are interpreting events (whether or not he was able to get into the Ark earlier and the tone of his statements) based on context more than anything.
And really, even before, Kelmomas never had loyalty to his father. It was explicitly a ploy to avoid being killed (from what I recall). That he was trying to be useful. The scene where Kellhus admonishes him seems like a big enough turning point.
- Despairs his father is probably sealed.
- Escapes with his mother's help and flees, having given up hope.
- Finds a new mom look-a-like, wow, what luck!
- Finds a bunch of people (The Mutilated) that he would be able to identify as Dunyain.
- Seeing as he knows what the Consult is (pretty sure), could reason joining them is the best bet to beating father and securing his mother.
Sorry for not adding this in my prior post, didn't notice the side discussion outside whether or not Kelmomas has agency within the Carapace.