I had time only for a brief chat with him late yesterday evening when he had calmed down but I garnered from him these facts.
1. On the evening in question the EI website was showing his flight as "on time".
2. About 30 minutes later he got the text that it was cancelled.
3. An hour after that he checked the website again and the flight was still showing "on time"
4. Confused at this point, he tried ringing various phone numbers to find out what was the correct situation but everyone was gone home.
His argument was that passengers were repeatedly being told to check the airline's website for the "latest information". In his case the latest information on the website was that his flight was on time. You could, of course, argue that the text message was the end of it, period. But why was there conflicting information? That is incompetence. For all he knew the situation could have changed again since he got the text message. I don't think that is unreasonable.
I still believe that putting them automatically onto the next flight (the A330) would have been the right thing to do because, according to CallBell, it was only an hour later. It's not as if it was the next day or later on after that. If a passenger has originally opted for, say a 10.am flight it would be reasonable to assume that a change to 11.00am is fine. I've had that done to me on, at the very least, a dozen occasions over the last few years (more than an hour later in some cases and not EI, btw) and very much appreciated that I was not required to do anything except if the new time didn't suit me. I did tell him about the A330 in the end but he wasn't interested. It transpires that were more in his party than two and they have cancelled and plan to go by ferry instead later on in the Summer.
Your points on the closure of the airports that the planes were stranded at are valid but it could also be argued that having so many aircraft out of position was poor decision-making.
People's opinions will always be coloured by their personal experiences and EI has never been good at managing things in a crisis but, to be fair, they've had such inept management over the years, that's no suprise.