I think I am seeing two major points to be learned here that so many contributors seem to want to ignore or even obliterate from the public domain:
1) Passengers' lives were thought to be endangered. Then during the recovery, Per Hadow thought he observed a degree of chaos - when he spoke to the press he no doubt described it using all the stuff which had made it into his brain up to that point coupled with some fair reasoning. I happen to know that there is nothing in a Ryanair safety briefing which adds to or subtracts from the stuff he spouted. In order to have moderated all his observations made to the press into statements of pure fact, he would need to have been debriefed and to know what I now know from elsewhere, wouldn't he? He quite clearly is not an idiot and I fail to understand why he should be expected to bother asking the company that ruffled his hair quite so thoroughly why they did it before he spoke to people interested in his overall experience. As we now know, they'd probably not have told him half of it anyway and he probably would have needed a fax machne to send his question and a computer to receive a response in days not minutes.
2) Something went wrong. 737NG's are to be built, operated and maintained by people that understand them well enough and practice their skill well enough to avoid ever finding themselves responsible for flying up at 11 or 12 km high and only then finding that they've missed something rather crucial to chances of people in their care remaining alive up there.
I don't think it is acceptable to claim stuff like 'It's not crucial because we train for it and we have a back up system. So all in all it is ordinary.'
I agree there may be interesting things to learn from comparing the experience and perception of the Ryanair pilot who happened to be a passenger that day with that of the non-pilot passengers. I don't doubt they were more relaxed about things than most. As I expect that person was sat in the front it would be naturally be interesting to know what they observed if they turned to look and/or sought to help others. One man's food is another's poison and all that.
Similarly, I don't suppose there were 16 people all fighting for priority boarding in an ambulance - I imagine they will have been advised to go/were simply led/carried away based on how they presented.
Passengers generally having been through something like that are expected to react like shaken passengers. Shove a microphone up their nose and who knows what might come out. But passengers are no more idiots than pilots in the grand scheme of things are they? Stick a microphone in a High Net Worth Ryanair pilot's face and ask about it and they poo-poo it, and even invite idiotic passengers to sue, right?
Let's please agree that people don't generally travel around the globe, publish websites, or accumulate and retain average net worth until they die these days by being idiots. Many who fly more, achieve less, and also don't know much about what goes on under the hood are no idiots either, are they?
Now then, why can't the serious subject matter i.e. how and why the fault occurred be discussed rather more soberly here?
BTW, unless I've missed it, we havent been told yet how high the cabin altitude rose so we really can make no judgement whatsoever in this thread on the effectiveness of the masks, can we?