If there’s a debate at all then the data are probably ambiguous or inconclusive, so let’s talk real human experience. Data says LSD is the best thing ever, and here’s one guy who has a terrible experience - is he wrong?
When a customer is complaining about e.g. "your site being broken", there's usually some real problem they're complaining about (though whether it's your problem to solve, or their ISP, or their computer, or their lack of knowledge of how web browsers work, etc. is another question entirely.) But the point being, if your data says the customer can't possibly be experiencing an issue — i.e. if your data disagrees with the customer's own lived experience of having a problem at all, with the data saying that e.g. the customer made a successful purchase, when the customer says they couldn't even load the site — then that should suggest that your tools for measuring your data are broken, or that there's something else equally-fishy going on (like a Man-in-the-Middle.)
None of this applies to medicine/psychology, because medicine never has the sort of data that could even theoretically be used to make a claim like "this is 100% working, and anyone who says they have a problem is lying" — the sort of claim where even a single counterexample would be enough to refute that statement, and therefore where a single counterexample would be valuable.
Rather, the sort of claims made in medicine are Bayesian confidence claims. The sort of (evidenced) claim that gets a treatment approved by the FDA, goes something like: "treatment X tends to be well-tolerated in population Y, while producing a positive outcome of power Z with benefits outweighing the measured side-effects."
No single anecdote (= clinical data) refutes that kind of statement. Instead, you need to compile and quantify a bunch of them (= clinical data meta-analysis) to actually make an argument for or against that claim.
Knowing this, any attempt someone might make to wield a single anecdotal claim to influence the credence you give a statistically-derived Bayesian-confidence statement of the safety and efficacy of a medical treatment — especially where you don't have an intuitive sense for how much data went into the statistics that led to the original statistical claim — should be regarded as an attempt to manipulate you with rhetoric, rather than honest debate praxis.
Which is not to say that the anecdote is false! You can totally believe that the person's lived experience is real, and empathize with them, and try to come up with solutions for their problem; while also taking as hokum any attempt by them to convince you that their anecdote generalizes.
And if someone tried to argue that LSD can never cause visual snow, a single anecdote is enough to refute that. Anecdotes are not always wrong in debate.
The only thing that comes to my mind reading this is that this is from an ignorant (and arrogant, but they usually go together).
Even if you tell me that you are the most renamed scientist in drugs I will still be thinking the same. Nobody wants addictions, bad trips or any problem with drugs and these still happen. Maybe you are the one that is "socially unprepared" to comment about this.
In attempts to (rightly) justify legalization, we now first have to appeal to the puritan-descendant US society and persuade it that it has great medicinal potential (because recreational potential is not enough). Consequently, you see overly exaggerated headlines that tout these substances as a miracle cure. Which, honestly, it might be for some people with certain conditions in a specific settings.
But, a person then reads "a new LSD study" and might conclude that their psilocybin trip was not a success, but maybe the LSD is going to change their world for the better.
If we just legalize these non-toxic substances, the conversation around them changes. The same happened to cannabis (where still nowadays, many people use the "medicinal" angle to justify their recreational habits so that they are not judged by the society, despite cannabis being legal in a number of US states).
Seriously, if I had a friend who couldn't handle alcohol, I would stop drinking with them and I would certainly refuse to take harder stuff with them. When I first had anxiety from smoking weed, my friends promptly told me weed is probably just not a drug for me to take and to take lower doses or to abstain from it entirely in the future-- and anxiety was a well-known (to me) possible consequence from weed.