What have they really done wrong here? The solution could have been delivered by Unity support eventually and it would likely be the same fix. They could have accidentally been presented snippets of code simply googling aspects of the bug, because google search automatically runs your search through their AI. They also could have not engaged with the LLM and shipped the game with the bug intact, or made other concessions, and the end result would have been lesser.
I am asking this in good faith despite how opinionated I already seem about it. I just don't 'get' the thought process and why we would expect a rational human being to behave differently in this situation. Solidarity and all that, yeah - but it's not like they're enthusiastic AI developers. They claim AI was used in no other part of development and what they produced was one of the most human and expressive video games out there.
So from where I'm standing, such resolute opposition just feels dogmatic, without really considering the current realities of software development. I'm half-way between 'this is an appropriate use of the technology, and surrounding market dynamics are the problem' and 'good boy developers get a little LLM as a treat'