What changed your mind upon re-read?
Well, the first time I read it, and excuses excuses, I was going fast and taking in a lot. It seemed like all of the events surrounding Kellhus, Kelmomas, and the WLW could also be ascribed to Kellhus seeing the possibilities as he always does, and avoiding the danger (in this scenario, Kelmomas would be misinterpreting what he was seeing).
The second time, it does in fact seem like Kelmomas is able to break the WLW's streak of White Luck. Now then, would the WLW have been successful in killing Kellhus without Kelmomas's intervention? I still don't think so, but there was an intervention that I can only explain as Kelmomas having a power beyond what he should.
All that being said, it is this alone that makes me believe it. All the things that came before just seem like the bizzaro imagination of an insane boy--thinking he had made a deal with the beetle sacrifice, believing he has the Unerring Grace, etc. And I still think the voice in his head is Samarmas.