It’s hard to believe he has achieved what he has without the support of his partner. That’s kinda the point of splitting assets upon divorce, because the law recognizes that partnership as (ideally) having been a shared effort to the benefit of both individuals.
But it’s not actually factually true - it’s her money according to the laws and contracts in place. If it were his money, he’d have it. He doesn’t, so it isn’t “factually” his money.
It’s only “his money” in a non-factual basis where we are implying something akin to “he earned it and she didn’t”.