Malevolence, such as the way Chris acted, but doing what he's done, 4 days before Obsidian's new game launches?I'm personally grateful to him that he has done so. "Saying anything bad about the people one used to work with reflects badly to the highest degree on the person saying it" is horseshit. It is silence, and acceptance of incompetence, mediocrity, and malevolence that is the true cancer infesting any and all societal constructs (such as a workplace).
And yes, doing what he did reflects badly on him. If I worked on another company, and was thinking about hiring Chris, this would surely make me think twice about it. If he pulled this with a past employer, he can do it with another employer as well.
And I must say, with your logic, burning bridges, you're very likely to go far professionally.
I can tell you that I worked with people, stopped working with them due to whatever reasons, and years later they came knocking on my door to work with me again, to our mutual benefit.
I'm sure that would happen if I decided to go on the internet, and badmouth them, with reason or not.