Well, I am also generally a stickler for the rules when it comes to these sorts of thing, owing to literally decades of trying to explain to people that "not accepting the claim that a god exists" is not the same as "claiming that a god exists.
Still though, I will play devils advocate here and say that this really is about semantics. I don't think people are talking about a scientific approach where Cloti and Clerith are two different claims and that Cloti being true is the default position. Clearly it's not, anyone with an ounce of logical thought understands this. But it is completely fair to say that we're no long in the default position. Imagine a courtroom where someone has been found guilty and 10 years later someone is coming along claiming they're innocent. Now sure, from a purely scientific point of view when we're talking about an argument where we are once again trying to ascertain whether this person is innocent, both parties should start from the null hypothesis. And yet you can't just walk up to the judge and use that logic to demand a retrial, first you need to prove that something was improper about the original trial.
What people who says Clerith have the burden of proof is essentially that this trial has already been done. It's been discussed a thousand times, they're lost a thousand arguments, the consensus conclusion is that Cloti has won the trial. So now when they're essentially trying to say "No, everything we know is wrong and the proof of your eyes is wrong", they're simply saying "well, that's an extraordinary claim, show me the extraordinary evidence.
Another way to look at it is this, the reason the burden of proof lies on Cleriths....is because Clotis have already fulfilled theirs. The ball is in their court as it were.
