Assuming it's really "the best possible hand", in the first round, Lalo played 15, which is a A-2-3-4-5 straight flush. Usogui played 36, which is 8-8-8-8-4. In a sense, Usogui got lucky that he played such a garbage card against a straight.
Now, since an ace has already been used, Lalo's 8 is a garbage 2-2-2-A-A full house, while Usogui's 39 is a 9-9-9-9-3 four-of-a-kind. There should be no more 9s or 7s left in the deck, and just a single ace (and a single 2).
But if that's the case, it makes me wonder what happens when your "best case scenario" contradicts with the opponent's "best case scenario". I guess they cancel each other out, and then the loser suffers a "calamity". If that's the case, I'm pretty sure the last round will be guaranteed to have a calamity, and the 4th will be extremely likely to have one.