At the time, I didn't bother to take screenshots of the tweets that were later deleted or the blog posts that were removed (since I didn't care enough and the designer had a relatively small audience).

In my heart of hearts, I was hoping the designer was just blowing off steam. I've been in the same situation before, where I think I'm right about a payment and the client disagrees, and it sucks, and I learned from the experience. I certainly didn't expect the designer to still be sore over it six months later, even after he claims he won the court case.