Nearly every crypto wallet I've created, I've initiated a transfer the same day. With the public ledger I can look up the first transaction for one of my wallet addresses and know with near certainty when that wallet was created. I wouldn't be surprised if this was the case for most people.
Who is he in that sentence? Do you mean the owner of the wallet who is absouletly very lucky, or the hackers that did a lot of investigating and reverse engineering to learn that the datetime was the seed. Was that luck or l337skillz?
It was both, like it usually is. All that investigating and reverse engineering would have been for nought if the program didn't have the problems in the first place. Hard work is often how you capitalize on luck. Sometimes the work is enough by itself, and sometimes it's not and the luck is integral.
Seems like they all were lucky that he luckily used a vulnerable password manager and knew the approximate parameters and time it was created. If he didn't get lucky, they might not have been paid.
They also found the seed was from time and knew when he had created it.
He got lucky there a little.