There is no circumstantial evidence, only a hypothesis which is not supported by any type of evidence. — Benkei
I'm not sure what you are disagreeing with.
The very definition of circumstantial evidence I cited from wikipedia is that it is very weak and compatible with mutually exclusive hypothesis. I am using circumstantial evidence in the way wikipedia describes.
Your issue with my statements seem to be you want to gate-keep the word evidence for the lawyer community.
If someone brings up a fact, and it seems plausibly tied to the case, I simply see no problem calling it evidence and analyzing from there. Questioning whether it counts as evidence or not seems a sterile debate. A detective tries to collect or record all the "evidence" in a case, without prejudice as to what's important enough to be called "evidence".
I have no problem saying "we have evidence" and concluding "based on the evidence, no scenario seems more likely", which is my position.
So, if you want to set yourself up as arbiter of what counts as evidence (what premises people are even allowed to propose for making an argument), then I am happy to continue there.
If we ignore the debate about evidence, our real difference, however, is you seem to think a lack of evidence proving (or even establishing as more slightly more likely) that the pandemic is a lab accident or purposefully released, means it's more likely it's natural.
Though I agree there's no evidence indicating a lab accident or purposeful release of the virus is more likely, I disagree that the natural occurring hypothesis is by definition the default hypothesis.
The paper "proving it's not engineered" is clearly bad faith. It is simply a non-refutable statement, as we cannot prove it's impossible to engineer a virus to not-appear-engineered, which would be a clear and strong motivation in the scenario where the virus is engineered. Indeed, it's fairly trivial to be convinced that such an engineering method is feasible, since both natural biology and biology manipulation are stochastic process so we can simply repeat techniques until they randomly appear natural.
So, if it's non-refutable to begin with, it's not science whatever these so called scientists are doing in the paper.
A scientifically valid approach would require, as a first step, a challenge to experts around the world to engineer viruses to appear natural and the team conducting the study trying to differentiate between these and other viruses actually taken from nature. If they are able to find the engineered virus in each challenge submitted by other labs around the world, then the idea they have such a detection ability becomes more credible. We would still need to wonder whether bio-weapons labs are not far, far ahead for such an exercise to be meaningful, but at least we have a starting point of a claim that has been properly submitted to refutation. So, this would be a refutable based framework for determining the engineered can be consistently differentiated from the natural by experts trying to defeat such detection, at least in the current state of civilian bioengineering.
Without such an adversarial framework, the claims these academics are making are simply their opinions based on non-refutable reasoning; i.e. they are not doing science as is understood by their contemporaries.
Now, that such academics are willing to squander their intellectual credibility and demonstrate they have either no basic critical thinking skills, no understanding of the scientific method or then they are simply liars, doesn't mean the virus is engineered, only that stupid is as stupid does.
Be that as it may, to be abundantly clear, I have not claimed here coronavirus has a "HIV gene" only that the we can't simply ignore a Nobel Prize winner (for work on HIV) claim that it does and it proves it's engineered (we need to actually analyse what we can before determining that this Nobel Prize winner's analysis makes no sense, which I bother to do, and by extension the Nobel Prize makes no sense as a standard of the "true-true" expertise).
I legitimately do not see any compelling reason to believe any of the scenarios (natural, accident, or on purpose) are ruled out in any significant way based on the information that's available.
All arguments, presented here or elsewhere of what is "more likely", seem to be mainly about the world view of the person proposing the argument. If one's world view is that "China would, like, for sure never release an epidemic with pandemic potential on their own population" then one is likely to conclude it's either natural or an accident. If one believes that "scientists are, like, totally competent and there's never, ever any reason to question scientific institutions are for the public good, even in totalitarian China", then one is likely to conclude it's not a lab leak. If one "doesn't believe in coincidences" in these tense geopolitical times, then one is likely to suspect foul play.
I realize Trump supporters are essentially rabid to believe it's not natural, so as to have a scapegoat. However, if there really is no compelling evidence one way or another, my view is that it only helps them to claim otherwise. Putting "credibility" behind the opposite of what Trump supporters, or Trump himself, believes simply because they believe it and entertaining the possibility "helps Trump", simply erodes the credibility put forth to back such counterclaims, and boost Trump supporters when they can show their basic ideas have not in fact been "ruled out" and alternative "debunking" has holes.
In my opinion, it's more productive to accept there is no compelling evidence (we just don't know, and I think likely at this point we will never know; and if we do find out, it won't be from any analysis that happens on the internet) because there is no compelling evidence, in order to move onto what we can know: which is if US intelligence suspected a bio-attack or then a bio-weapon leak, obviously the US administration did not do anything about it, for instance contain it when it was still possible to have an effective containment policy (what I advocated when I first joined this thread many moons ago) and when they failed to act on that, followup with further failure to prepare; and, more importantly, the global system, and in particular the US, was knowingly vulnerable to such a pandemic threat because ignoring it maximized short term profits: In other words, the market is not efficient at allocating resources, and, in addition, the US security establishment does not bother much to ensure the US is secure from threats to US citizens that don't happen to coincide with arms sales and imperialism (i.e. either way, US citizens aren't the object of "US security"; well, not in the way the republicans previously liked to imagine). So, regardless of the scenario of the emergence of the pandemic, we can draw the same conclusions: If it was an attack then it's an easy attack exploiting a weakness elites in the West didn't care to fix because of money and they don't care about the poor as they can get top-notch care and just hide from the virus anyways. If it's a lab leak, then obviously far more regulation is needed about these labs and drastically or fully cutting plane travel ties with any dystopian totalitarian state which cannot be trusted to police best practices. If it's natural, then capitalism as we know it today, in particular in the US, was obviously unprepared for a known risk along with bad public health policies in general that amplify that risk, unwilling to do a flight freeze in the critical moment because "will someone please think of the airplane stonks!", lacking the institutions to keep society stable in such a health and economic crisis, yet unhesitating to bail out the wealthy while they huddled in their compounds and traveled to islands and yachts and New Zealand to insulate themselves from the consequence of their governing system. I.e. we can draw sound conclusions about our leaders and sound policy recommendations about the current system in any of the potential scenarios.