I personally understood (and still understand) it to mean that had wished it happened to him because he had no mother to care about his death. Not just wishing him to die (or become comatose or paralyzed), but to signify how worthless his life was as a bastard. It was after I joined the forum that I realized others do not read it that way.
I agree with this. Grief does not make us monsters, it just unleashes the demons we already carried inside.
I think Ned was not a good liar, so he probably just avoided the whole situation by not talking about it. I agree that it did not help the situation at all.
I do agree that she deeply cared about all her kids, but I also agree that she did not treat Arya very well. There was something about how Arya was treated that led both girls to believe Arya was bastard just like Jon. And I think it is telling that Arya takes that suspicion to Jon (the one treated differently) and Sansa takes it to Cat (the one treating one of the kids differently based on his baseborn status). Since we know Ned did not treat the boys differently and actually saw her dear sister in Arya, it must have been Cat. but that is just a suspicion.
He had stayed away specifically for this reason:
But this was NOT about Cat. This was about Jon saying goodbye to a dear brother, why should everything be about Cat?!
Really?! Sansa is the girl that says this after Joffrey has already cut Mycah and is attacking Arya (Sansa's younger sister) with naked steal while she has only a piece of stick to defend herself:
It is VERY clear to me why would Arya expect the worst from Sansa!
A very good point. Somebody upthread used the words "understandable and forgivable" as if one leads to the other, which looking at the discussion here is definitely not true.
I agree with this and also wanted to point out that while everyone is very fixated on the context relating to Cat's behavior towards Jon and blaming Ned about his decisions, there is a context surrounding Ned's frame of mind too.
So, while the only thing that happened to Cat was that her pride was severed, Ned had come back from a war, having lost all (but one) of his family members in a span of a year, was forced (strategically by his mentor) to marry the fiance of his older brother (who hasn't let go of her crush on him after many years of happy marriage to Ned), and had witnessed the death of her sister and was carrying her body. He had brought a family member (his own bastard son) with him. That is so much trauma to have gone through but he actually never got any solace from his wife (not in these issues). Cat was not the biggest victim, only the pettiest.