Indeed, this is supposedly the hijacker who shot the captain according to one of the more outrageous conspiracy theories. Although Vixen supposedly no longer believes that the captain was shot, I guess we still have to listen to the residual speculation over and over again. Just as it was suspicious strange curious that the captain's body wasn't recovered to make sure he wasn't shot in the head, had a heart attack, or suffered from debilitating constipation that doomed the ship, it remains suspicious strange curious that the official investigation didn't chase down the story of the "unauthorized" corpse on the bridge—according to all those wannabe investigators from their comfy armchairs.
But Vixen says variously, "I never made any claim to expertise." (Granted she does sometimes, but this remains her anchor position.) But this seems true only because she doesn't actually state all her assumptions. See, every allegation of fact—especially those that involve specialized knowledge or understanding—comes with the tacit assumption, "I know what I'm talking about." That's why one of the most powerful questions you can ever ask in a debate is, "How do you know that?"
When a claimant says something like, "A ship can't float on its 'superstructure,'" there's a tacit assumption for how that knowledge was validated. Perhaps the claimant came by the statement from a secondary source she trusts. Or she may have concluded it from her own understanding, recollection, or assumption. But all roads eventually lead to the claimant needing to know what she's talking about, either to vet her sources and their claims, or to elucidate the reasoning behind original conclusions. The answer to, "How do you know that?" will ultimately have an answer that implicate's the claimant's own competence. It simply can't be ignored. So things like, "I never claimed to be a physicist," are straw men. As soon as the claimant makes an argument sounding in physics, some competence in physics has been asserted as a tacit premise—a tacit assumption.
Similarly if someone says that high explosives produce high temperatures, and that therefore metal objects subjected to them should exhibit evidence consistent with high temperature, that necessarily implicates a claim of enough expertise in explosives and metallurgy to make that statement. The unstated assumption is always, "...and I know what I'm talking about." You don't get to say later, "I never claimed to be a metallurgy expert," or "I never claimed to be an explosives expert." Some profession of competence is necessarily implied in the claim and cannot simply be ignored.
Among armchair detectives, the answer to, "How do you know that?" too often comes out as, "It's common knowledge," or vague allusions to "the laws of physics" without further detail. And then sometimes you get a comically inept expression of how the physics is supposed to work, but at least it's an attempt.
Of course the basic rationale of modern science and the whole point of expertise in general is that what people think they know commonly is often wrong. Experts are experts quite often because they have knowledge that uninformed intuition or poorly reasoned speculation can't correctly supply. Experts have experience that incorporates knowledge that can't easily be obtained any other way. Knowing how to investigate something correctly often requires investigating things as a novice, making mistakes, and being corrected by your mentors until you learn the art of avoiding the mistakes. But since the value of expertise is in correcting the mistakes that come from poor recollection, uninformed intuition, and other insufficient sources, armchair detectives have to be constantly amenable to correction if they want to have any sort of credibility. Insisting that their "common sense" or poorly-recalled O-levels should still trump the judgement and knowledge of experts who can explain their error is simply bad faith. The assumption, "...and I know what I'm talking about," becomes a failed premise.
Sadly, armchair detectives are gonna armchair. But after their ignorance is exposed, it devolves to pure rhetoric trying to sidestep, defuse, or paint over that exposition. Then we start to see the straw men. "You don't need a degree in physics to discuss the sinking of a ship," or "I just want to discuss current affairs," etc. Well, if you're making claims that amount to conclusions drawn from allegations of complex physical behavior, then you just might need such a degree (or its equivalent). If you're going to say that the science of roll stability (metastable height etc.) means a ship must inevitably "turn turtle," you will simply need to be able to talk about that science without getting hopelessly befuddled over the simple elements of the theory, such as points and vectors. You can't botch those badly, confuse it all with buoyancy, and still pretend that you've presented a good-faith argument.
And you don't get to say that you just want to have a "discussion" or a "polite debate" or jabber about "current events" when you are quite patently challenging your betters. Accusing people of smuggling dangerous isotopes, of hijack and murder, or of coverup, dereliction, or incompetence in investigation is not just idle curiosity. You are more responsible for knowing what you're talking about when you hurl those accusations. Sadly so much of Vixen's schtick is to make a claim or argument and then bald-facedly deny the essential nature of the claim."It's not a conspiracy theory!" even when it very patently is. Again, bad-faith arguments that deserve no further attention except perhaps as fodder for bored skeptics.
It all comes down to trying to walk the fine line between claiming to be the smartest person in the room and also not having to demonstrate any actual smartness. The claimant is somehow smarter than 99.9% of humanity, but also somehow her critics are on the hook to indulge her failed memory and her numerous "syntax" problems and "typos." Holding her to high standards of "triple-niner" performance is somehow mean-spirited heckling. She doesn't have time for the petty stuff like actually learning vector analysis or what ″ actually indicates. How dare anyone suggest she's not smart enough to question experts from her postgraduate armchair and declare "Discussion over!" as soon as she's backed into a corner!