The issue here concerns First Amendment right to free speech, and its limitations. Has nothing to do with restoration. Once the guy from CGC stopped providing opinions (which all grading companies do when they inspect, grade, and slab a card or comic book) and started to publicly slander the restoration company, he got in hot water. Should have known better.
EDIT: Here is a link to an article that explains that CGC had concerns that the comics were not being restored but were being reprinted, recreated, and or faked. In other words, the comics were counterfeits. That's not an issue of restoration. It an issue of whether fraud was committed based on allegations of fakes and recreations. Then, the restorers filed a defamation suit, which of course, involves the First Amendment.
https://www.pennlive.com/news/2019/1...slandered.html
EDIT # 2, quote from attached appeal: "It bears emphasizing here that within the industry, a comic book’s value becomes greatly diminished once any component is substituted or removed, such as 'trimming' off the damaged edges of a page or 'reprinting' covers with a Xeroxed copy. Such practices both mar the quality of the original comic book and mislead collectors about how much of the original work remains. 'Re-creation' is often synonymous with 'fake' or 'counterfeit.' See Page 5 of attached opinion.
https://www.pacourts.us/assets/opini...9280486128.pdf