Wales actually covers this at length in his book: https://en.wikipedia.org/wiki/The_Seven_Rules_of_Trust

He himself admits it's a complicated situation, and argues both his own and Sanger's position.

Combined with the context provided by all the parent comments here, it's quite difficult to argue good faith given the interview was also specifically on the book tour. There are many different and actually productive ways the interview could have talked about the conflict between Wales and Sanger.