Couldn't someone else then simultaneously register the hash of the same domain with a different seed? Neither of you would know of the duplicate until you revealed your seeds.
What's the chances of simultaneous transactions? (That's a question, not a snarky statement).
There aren't any. That's what the article was about: The order of the transactions in a block.
Sorry I shouldn't perhaps have said transactions - the parent asks what to do with simultaneous requests for to reserve a unique unduplicable good, it was the simultaneity of identical requests I was asking about rather than the impossible simultaneity of processing the blockchain transactions.