I just have one word to share here.
Accountability.
If a process or SOP was put in place where CGC could track who checked it in, graded and encapsulated the book, they could determine where in the chain of custody the damage most likely happened. Once you witness someone get canned for damaging a book/books it emphasizes the need to be careful. Damaged to books won’t happen as often as it does. Heck, even dope dealers have someone who walks the processing floor to make sure no shenanigans are happening.
In the case of Thomas’s copy of Captain Marvel 28 you are looking at a difference of $20,000.00 based on the last auction result. It’s no minor matter.