well, that still means they have to follow Irish law. Just like shipping companies register their ships in other countries, that means they have to follow their laws too.
yes, but that's not the point of GP comment. Saying "Ireland alone has $50B turnover" might make someone think: "Wow, if they make so much money from such a small country, then how much do they make in the entire Europe?". And the answer to that is: $50B. There's not a single euro-cent is earned in Europe that does not go through Ireland.