Danny Ocean wins the bet in Ocean's Twelve because his crew had already swapped the real Fabergé egg, with inside help from Gaspar LeMarc, before François Toulour made his attempt.
LeMarc is Toulour's own mentor, and he wanted to humble his protégé. That detail changes how the whole film reads. Toulour believes he is racing the crew to a prize, but the prize was already gone, so his elaborate approach was a performance for an empty case.
The Night Fox stays ahead of the crew for most of the film for a concrete reason: after the failed Amsterdam heist, it is clear he is the one who tipped off Terry Benedict, and he then bets Danny that he can reach the egg first. That lead explains why the early jobs collapse, and it also explains why the crew can look outmatched while holding the winning card. Our take: this is the cleverest part of the structure, because the crew appears to be one step behind the Night Fox while the real swap has already happened (the suggestion is that the crew let him believe he was ahead).
The consequences are neat. Toulour loses the bet and pays the debt, so Benedict is repaid. Reuben Tishkoff delivers the money and swears off further heists against Benedict's casinos. Isabel Lahiri discovers that her father is LeMarc, which ties the detective subplot to the thief subplot.
Two other plot turns feed the finish. Tess Ocean poses as the actress Julia Roberts, a twist that exists because Roberts' pregnancy with twins was reported on June 1, 2004, just as she was about to start work, and the script was reworked around it, as CBS News reported at the time. And when the scheme is interrupted and most of the crew is in custody, it is Linus Caldwell's mother, an FBI agent, who gets them freed, so the rescue comes from inside the family circle rather than from a last gadget.
Compared with the rest of the series, the payoff is built differently. Ocean's Eleven is the setup that creates Benedict's grievance, and this sequel turns that grievance into a deadline and then into a wager between two thieves. Our take: the film is loose and playful, and viewers who want a tight procedural may prefer Ocean's Thirteen.