That egg was totally still edible, even if you pierce it for the cooking, it should be good for at least a few days. If you do it right, it can be weeks.
In Germany you can buy cooked eggs in the super market and they are not refrigerated.
This article was weird, in that he went through the whole thing about how effective the layers are without also mentioning there was a hole through all of them other than the egg white (until the end).
That’s true, at least I would have eaten it. I did leave out boiled eggs with holes after cooking them for at least a day in the past. It depends of course, I don’t live in a super humid and hot climate, results may differ there.
The egg cooker is a mystery to me. What is the hole for? I hard-boil eggs by heating a pot of water containing the eggs. Why would you puncture the shell?
I do not know about TFA and the egg cooker, but I usually boil the water first so I can pull the eggs out at a specific time (6:30 to 7:00) so the yolk is gooey. When I put an egg into boiling water without putting a hole through to the air sac, I think there's a higher chance that the egg will crack and spew albumen throughout the boiling water.
It addresses this in the article, but in countries that wash the bacterial layer off (like the US), they have to be refrigerated. This is to minimize salmonella contamination, EU deals with this by vaccinating hens against salmonella instead.
Does the same apply for cooked eggs? I would have thought all bacteria is gone from the shell after the process, making EU and US cooked eggs virtually the same. A short search seems to agree with that.
it is very, very unlikely that a fully cooked egg that sat out overnight would have enough bacterial growth (and toxin production by bacteria) to represent a threat to a normal person with a typical immune system.
If the egg had bacteria already growing in it (which is also unlikely) then it's possible that enough of the bacterial toxins could accumulate and be inside when you eat it.
There are probably a number of extremely rare scenarios which would modify the situation but this article includes a lot of words and facts only to come to the unlikely conclusion.