IMHO it was in the grey zone (the one for loading and unloading only) for a couple reasons.
It was the third post. It’s not like there was a long string of lamentations about a beloved figure and he came in and laid out a nutty turd.
I’m not arguing the ruling (grey zone could go either way), just understanding the question: is it a general rule that you can’t speak ill of the deceased in an RIP thread.
Thinking of it in a slightly different way gave me a bit of perspective. Consider:
Notice I only changed the names. Both posts are completely neutral. Would the third post still warrant a warning?
Note I’m not making this a liberal/conservative thing. Similar to Giuliani, Koch was both loved and reviled by many. Those of us who grew up in and around NYC during the Koch years (Giuliani years) have a completely different perspective on him.