Someone got very angry with me

a few weeks ago.  It was a completely unexpected blistering and furious reaction to a genuine question on my part. It was perhaps the "diatribe" of which they had accused me.
At the time I was almost too stunned to do anything. Eventually I tried to defend myself. Then, realising it was probably just making matters worse, I  backed off.  It isn't someone I know well. I don't like or dislike her particularly as I don't really know her. I did think it was probably out of character and I did wonder if something else was wrong. 
Then, much more recently, I learned this same person is ill. It was mentioned to me by chance. I'm glad it was mentioned  because I suspect that, as much as anything else, I just happened to be the "someone" this person used to try and cope with the fear, anger and frustration the diagnosis must have brought about. 
Middle Cat has told me off more than once for avoiding arguments, for not "defending myself." Apparently I am not "assertive" enough and I "give in" too easily. (Mind you, try it with her and I get told I need to take her advice and do as I am told.)
I will admit I have a strong aversion to arguments. I do "back off" and I do avoid the sort of arguments that might lead to harm. (I am also more than happy to "argue" about something if I am interested in the topic.)
So I'll admit I hesitated but I did, and still do, feel genuinely concerned for the person who is ill, so I sent her an email just wishing her the best possible outcome. I wasn't sure if it would be ignored or I would get a blistering reply. At least I would have tried. I actually got a "thank you". Nothing else but it was more than enough. It made me almost certain that my belief about the possibility there was something else wrong was correct.
If I had "defended" myself and become angry then it might not have been possible to say anything. There would have been one less tiny piece of support for someone going through a very difficult time. Rather than respond in kind it was better to let someone know I am concerned for them.
I've been thinking a lot about this. There was a television program here recently. I didn't see it but it was called "Look me in the eye" and apparently involved bringing together people who were estranged and asking them to do no more than sit there and look directly at one another. I don't know what the results were but the trailers suggested that, at least for some, the process worked.
I think though that what it takes most of the time is nothing more than for one person to reach out - and the other to accept.
I'll put the kettle on too.