However they sent a 3090 GPU and a prototype cooler for that specific board, which they mounted on a 4090 board which has a potentially different layout and was not tested.

Imagine they were a small company , whose first product was the LTT screwdriver, and they had sent an early prototype to a YouTuber who complained that none of the bits he had laying around worked on that screwdriver, so no one should buy the LTT screwdriver because it just doesn't work. When people complain that they weren't doing the product justice by testing it with the wrong things they replied "I'm not spending money retesting a screwdriver that no one should buy because it's useless". Then turned around and sold the prototype at an auction. Then when people complained they said "we didn't sell it, we auctioned it for charity, and have already sent money to replace it" having sent the email agreeing to pay seconds before saying that stupid excuse.

They did a LOT of wrong things there, a bad review is the least of the problems. For all I know the product is in fact shit, but because of their methodology, plus all that they did afterwards, I can't trust that they would ever produce an honest review of the product. And this is a house of cards, as soon as one review can't be trusted, no review can be trusted. Can you assure that they used proper protocol when testing other things if they can't even use the GPU that was sent together with the cooler? And that when people point this instead of retesting they just dig themselves deeper into "we're right"... Plus you should watch the GN video, they point a LOT of inconsistencies and errors in other videos, showing that the cooler is NOT an isolated thing.