Setting trolling aside, this could also be an act of a person who is very scared and angry at the diagnosis, and who is dealing with the news by looking for external factors they can blame and redirect their feelings toward. It's a very human reaction for someone in a terrible situation, and I would be inclined to give them some grace for it.
Understanding is not agreeing though. Of course none of this is on you. Everybody deals with stress in their life, and if code review bickering was the worst thing they faced, I'd consider that pretty lucky indeed. As others mentioned, you can't control how others deal with adversity and emotions, and this includes this LinkedIn outburst. No need to feel guilt here whatsoever (though perhaps worth thinking about professional disagreements in general, and ways of handling those conversations in a productive rather than adversarial manner).
Understanding is not agreeing though. Of course none of this is on you. Everybody deals with stress in their life, and if code review bickering was the worst thing they faced, I'd consider that pretty lucky indeed. As others mentioned, you can't control how others deal with adversity and emotions, and this includes this LinkedIn outburst. No need to feel guilt here whatsoever (though perhaps worth thinking about professional disagreements in general, and ways of handling those conversations in a productive rather than adversarial manner).