The Billet Labs prototype copper water cooler. It was hand made and precision engineered to work with a specific graphics card. Billet Labs loaned Linus the cooler, Linus reviewed it, but on the wrong graphics card, pilloried Billet Labs and basically said their prototype was trash.
Then Linus auctioned it off instead of returning it. Billet Labs tried to contact Linus about getting him to return it, and he just ignored their emails and phone calls for nine weeks until this video came out. He then offered them some small pittance of money to make up for it. This was experimental technology and any competitor could buy it to reverse engineer their design. Billet Labs is not a big company and from the members only "apology" video LTT released it showed that the cost of the prototype was several thousand dollars, not including the countless hour spent in research, testing, and development.
There is a very good chance that Linus' actions may have caused enough financial harm to Billet Labs that they might close down.
Time stamp for the exact place GN talks about this.
https://youtu.be/FGW3TPytTjc?t=1710