Creating a transaction at the same exact second as another one

[Tfs]

Thank you to all, especially gmaxwell for the detailled answer and the word "topological".

In fact my question comes from the recent address bc1qhtawge4km6juhlkrnvt7qjahhsc96qdlgf3c8t which got 10,000 btc on  july 4th, 2025 at block 903978 and in the same block received some dust with an OP_RETURN mentionning 342038203135203136203233203432, which was discussed a long time ago on this forum in spanish https://bitcointalk.org/index.php?topic=1575193.0