What, in your opinion, should the rules be for YouTube Reviews?

Recently, the OCD Hifi channel posted a David vs. Goliath takedown of Constellation. He does not own the unit, has none to handle personally, and bases his critique upon his examination of publicly available photos and their website patter. His video reads Constellation the riot act for their paltry construction and then questions their chutzpah for putting lipstick on a pig and suckering people in. He then contrasts the Constellation by comparing it to Jeff Rowland’s stuff, which his dealership carries.

Personally, I don’t own Constellation nor would I pay $55k for an amp. But I’m wondering what folks here — with intimate knowledge of the differences between seeing photos and handling gear -- think about this kind of takedown.

I’m imagining a spectrum of argument, pro and con this video.

On one end of the spectrum, one might argue for the OCD guy — "Look," one might say, "this is just such an easy target that all he’s doing is calling out a scam based on evidence that is so obvious that anyone could see it. OCD has Constellation dead to rights and he just bothered to make it interesting with a video. He doesn’t need better evidence to do such an obvious takedown. This is called "market correction"." Or words to that effect.

On the other end, one might say, "A channel with 11k subscribers had some duty of due diligence. A take-no-prisoners critique of a product requires that he at least have one to listen to, open up, etc. His willingness to draw a contrast with his own line of products is more than a convenient point of comparison of his video — it’s the main point, however disguised. What this amounts to is an unfair takedown of a product and company to help boost his own sales."

Or maybe there are takes in between?

In short, here I’m wondering about these questions:

"What kind of evidence is necessary for a public-facing critique?"
"What are the responsibilities of a public-facing review?"
"What kinds of reviews are appropriate for dealers to do?"

Be interested to hear from those in the industry, consumers, or reviewers on this question.