It doesn't sound to me as though ECH felt that he was "resorting to" using all capitals--it seemed like he was just trying to see what he'd written. And if his grandchild hadn't taught him "netiquette", I don't see how it's his fault for not knowing. I personally don't find caps offensive, but then I am still pretty green re: being on the internet.
Having said that, I will say that it might have helped, had he offered some explanation at first...but then again, why would anyone if they had no idea that what they were doing might be offensive?

I think one thing that we might learn is that it can be a mistake for us to assume that every newcomer knows what they're doing. People venture on to the internet for the first time every day; and if they come on here...well, why not? And having said that, I am of the opinion that ECH could have been a bit more gracious. I don't think anyone "jumped on" him.

Let me paraphrase something I said at our church meeting last night, in response to complaints about our new and very young Youth Director: I think it would be a good thing if we concentrate more on helping someone succeed, before being so quick to pounce on them for failing.